## edge-20.4.4

This edge release fixes a packaging issue in `edge-20.4.3`.

_From `edge.20.4.3` release notes_:

This edge release adds functionality to the CLI to output more detail and
includes changes which support the multi-cluster functionality. Also, the helm
support has been expanded to make installation more configurable. Finally, the
HA reliability is improved by ensuring that control plane pods are restarted
with a rolling strategy

* CLI
  * Added output to the `linkerd check --proxy` command to list all data
    plane pods which are not up-to-date rather than just printing the first
    one it encounters
  * Added a `--proxy` flag to the `linkerd version` command which lists all
    proxy versions running in the cluster and the number of pods running
    each version
  * Lifted requirement of using --unmeshed for linkerd stat when querying
    TrafficSplit resources
  * Added support for multi-stage installs with Add-Ons
* Controller
  * Added a rolling update strategy to Linkerd deployments that have
    multiple replicas during HA deployments to ensure that at most
    one pod begins terminating before a new pod ready is ready
  * Added a new label for the proxy injector to write to the template,
    `linkerd.io/workload-ns` which indicates the namespace of the workload/pod
* Internal
  * Added a [security policy](https://help.github.com/en/github/managing-security-vulnerabilities/adding-a-security-policy-to-your-repository)
    to facilitate conversations around security
* Helm
  * Changed charts to use downwardAPI to mount labels to the proxy container
    making them easier to identify
* Proxy
  * Changed the Linkerd proxy endpoint for liveness to use the new `/live` admin
    endpoint instead of the `/metrics` endpoint, because the `/live` endpoint
    returns a smaller payload
  * Added a per-endpoint authority-override feature to support
    multi-cluster gateways

## edge-20.4.3

**This release is superseded by `edge-20.4.4`**

This edge release adds functionality to the CLI to output more detail and
includes changes which support the multi-cluster functionality. Also, the helm
support has been expanded to make installation more configurable. Finally, the
HA reliability is improved by ensuring that control plane pods are restarted
with a rolling strategy

* CLI
  * Added output to the `linkerd check --proxy` command to list all data
    plane pods which are not up-to-date rather than just printing the first
    one it encounters
  * Added a `--proxy` flag to the `linkerd version` command which lists all
    proxy versions running in the cluster and the number of pods running
    each version
  * Lifted requirement of using --unmeshed for linkerd stat when querying
    TrafficSplit resources
  * Added support for multi-stage installs with Add-Ons
* Controller
  * Added a rolling update strategy to Linkerd deployments that have
    multiple replicas during HA deployments to ensure that at most
    one pod begins terminating before a new pod ready is ready
  * Added a new label for the proxy injector to write to the template,
    `linkerd.io/workload-ns` which indicates the namespace of the workload/pod
* Internal
  * Added a [security policy](https://help.github.com/en/github/managing-security-vulnerabilities/adding-a-security-policy-to-your-repository)
    to facilitate conversations around security
* Helm
  * Changed charts to use downwardAPI to mount labels to the proxy container
    making them easier to identify
* Proxy
  * Changed the Linkerd proxy endpoint for liveness to use the new `/live` admin
    endpoint instead of the `/metrics` endpoint, because the `/live` endpoint
    returns a smaller payload
  * Added a per-endpoint authority-override feature to support
    multi-cluster gateways

## edge-20.4.2

This release brings a number of CLI fixes and Controller improvements.

* CLI
  * Fixed a bug that caused pods to crash after upgrade if
    `--skip-outbound-ports` or `--skip-inbound-ports` were used
  * Added `unmeshed` flag to the `stat` command, such that unmeshed resources
    are only displayed if the user opts-in
  * Added a `--smi-metrics` flag to `install`, to allow installation of the
    experimental `linkerd-smi-metrics` component
  * Fixed a bug in `linkerd stat`, causing incorrect output formatting when using
    the `--o wide` flag
  * Fixed a bug, causing `linkerd uninstall` to fail when attempting to delete
    PSPs
* Controller
  * Improved the anti-affinity of `linkerd-smi-metrics` deployment to avoid
    pod scheduling problems during `upgrade`
  * Improved endpoints change detection in the `linkerd-destination` service, enabling
    mirrored remote services to change cluster gateways
  * Added `operationID` field to tap OpenAPI response to prevent issues during
    upgrade from 2.6 to 2.7
* Proxy
  * Added a new protocol detection timeout to prevent clients from consuming
    resources indefinitely when not sending any data

## edge-20.4.1

This release introduces some cool new functionalities, all provided by our
awesome community of contributors! Also two bugs were fixed that were introduced
since edge-20.3.2.

* CLI
  * Added `linkerd uninstall` command to uninstall the control plane (thanks
    @Matei207!)
  * Fixed a bug causing `linkerd routes -o wide` to not show the proper actual
    success rate
* Controller
  * Fail proxy injection if the pod spec has `automountServiceAccountToken`
    disabled (thanks @mayankshah1607!)
* Web UI
  * Added a route dashboard to Grafana (thanks @lundbird!)
* Proxy
  * Fixed a bug causing the proxy's inbound to spuriously return 503 timeouts

## edge-20.3.4

This release introduces several fixes and improvements to the CLI.

* CLI
  * Added support for kubectl-style label selectors in many CLI commands (thanks
    @mayankshah1607!)
  * Fixed the path regex in service profiles generated from proto files without
    a package name (thanks @amariampolskiy!)
  * Fixed an error when injecting Cronjobs that have no metadata
  * Relaxed the clock skew check to match the default node heartbeat interval
    on Kubernetes 1.17 and made this check a warning
  * Fixed a bug where the linkerd-smi-metrics pod could not be created on
    clusters with pod security policy enabled
* Internal
  * Upgraded tracing components to more recent versions and improved resource
    defaults (thanks @Pothulapati!)

## edge-20.3.3

This release introduces new experimental CLI commands for querying metrics using
the Service Mesh Interface (SMI) and for multi-cluster support via service
mirroring.

If you would like to learn more about service mirroring or SMI, or are
interested in experimenting with these features, please join us in
[Linkerd Slack](https://slack.linkerd.io) for help and feedback.

* CLI
  * Added experimental `linkerd cluster` commands for managing multi-cluster
    service mirroring
  * Added the experimental `linkerd alpha clients` command, which uses the
    smi-metrics API to display client-side metrics from each of a resource's
    clients
  * Added retries to some `linkerd check` checks to prevent spurious failures
    when run immediately after cluster creation or Linkerd installation

## edge-20.3.2

This release introduces substantial proxy improvements as well as
new observability and security functionality.

* CLI
  * Added the `linkerd alpha stat` command, which uses the smi-metrics
    API; the latter enables access to metrics to be controlled with RBAC
* Controller
  * Added support for configuring service profile timeouts
    `(x-linkerd-timeout)` via OpenAPI spec (thanks @lewiscowper!)
* Web UI
  * Improved the Grafana dashboards to use a globing operator for Prometheus in
    order to avoid producing queries that are too large (thanks @mmiller1!)
* Helm
  * Improved the `linkerd2` chart README (thanks @lundbird!)
* Proxy
  * Fixed a bug that could cause log levels to be processed incorrectly

## edge-20.3.1

This release introduces new functionality mainly focused around
observability and multi-cluster support via `service mirroring`.

If you would like to learn more about `service mirroring` or are interested in
experimenting with this feature, please join us in
[Linkerd Slack](https://slack.linkerd.io) for help and feedback.

* CLI
  * Improved the `linkerd check` command to check for extension server
    certificate (thanks @christyjacob4!)
* Controller
  * Removed restrictions preventing Linkerd from injecting proxies into
    Contour (thanks @alfatraining!)
  * Added an experimental version of a service mirroring controller, allowing
    discovery of services on remote clusters.
* Web UI
  * Fixed a bug causing incorrect Grafana links to be rendered in the web
    dashboard.
* Proxy
  * Fixed a bug that could cause the proxy's load balancer to stop processing
    updates from service discovery.

## edge-20.2.3

This release introduces the first optional add-on `tracing`, added through the
new add-on model!

The existing optional `tracing` components Jaeger and OpenCensus can now be
installed as add-on components.

There will be more information to come about the new add-on model, but please
refer to the details of [#3955](https://github.com/linkerd/linkerd2/pull/3955) for how to get started.

* CLI
  * Added the `linkerd diagnostics` command to get metrics only from the
    control plane, excluding metrics from the data plane proxies (thanks
    @srv-twry!)
  * Added the `linkerd install --prometheus-image` option for installing a
    custom Prometheus image (thanks @christyjacob4!)
  * Fixed an issue with `linkerd upgrade` where changes to the `Namespace`
    object were ignored (thanks @supra08!)
* Controller
  * Added the `tracing` add-on which installs Jaeger and OpenCensus as add-on
    components (thanks @Pothulapati!!)
* Proxy
  * Increased the inbound router's default capacity from 100 to 10k to
    accommodate environments that have a high cardinality of virtual hosts
    served by a single pod
* Web UI
  * Fixed styling in the CallToAction banner (thanks @aliariff!)

## edge-20.2.2

This release includes the results from continued profiling & performance
analysis on the Linkerd proxy. In addition to modifying internals to prevent
unwarranted memory growth, new metrics were introduced to aid in debugging and
diagnostics.

Also, Linkerd's CNI plugin is out of experimental, check out the docs at
https://linkerd.io/2/features/cni/ !

* CLI
  * Added support for label selectors in the `linkerd stat` command (thanks
    @mayankshah1607!)
  * Added scrolling functionality to the `linkerd top` output (thanks
    @kohsheen1234!)
  * Fixed bug in `linkerd metrics` that was causing a panic when port-forwarding
    failed (thanks @mayankshah1607!)
  * Added check to `linkerd check` verifying the number of replicas for Linkerd
    components in HA (thanks @mayankshah1607!)
  * Unified trust anchors terminology across the CLI commands
  * Removed some messages from `linkerd upgrade`'s output that are no longer
    relevant (thanks @supra08!)

* Controller
  * Added support for configuring service profile retries
    `(x-linkerd-retryable)` via OpenAPI spec (thanks @kohsheen1234!)
  * Improved traffic split metrics so sources in all namespaces are shown, not
    just traffic from the traffic split's own namespace
  * Improved linkerd-identity's logs and events to help diagnosing certificate
    validation issues (thanks @mayankshah1607!)

* Proxy
  * Added `request_errors_total` metric exposing the number of requests that
    receive synthesized responses due to proxy errors

* Helm
  * Added a new `enforcedHostRegexp` variable to allow configuring the
    linkerd-web component enforced host (that was previously introduced to
    protect against DNS rebinding attacks) (thanks @sannimichaelse!)

* Internal
  * Removed various es-lint warnings from the dashboard code (thanks
    @christyjacob4 and @kohsheen1234!)
  * Fixed go module file syntax (thanks @daxmc99!)

## stable-2.7.0

This release adds support for integrating Linkerd's PKI with an external
certificate issuer such as [`cert-manager`] as well as streamlining the
certificate rotation process in general. For more details about cert-manager
and certificate rotation, see the
[docs](https://linkerd.io/2/tasks/use_external_certs/). This release also
includes performance improvements to the dashboard, reduced memory usage of the
proxy, various improvements to the Helm chart, and much much more.

To install this release, run: `curl https://run.linkerd.io/install | sh`

**Upgrade notes**: This release includes breaking changes to our Helm charts.
Please see the [upgrade instructions](https://linkerd.io/2/tasks/upgrade/#upgrade-notice-stable-270).

**Special thanks to**: @alenkacz, @bmcstdio, @daxmc99, @droidnoob, @ereslibre,
@javaducky, @joakimr-axis, @JohannesEH, @KIVagant, @mayankshah1607,
@Pothulapati, and @StupidScience!

**Full release notes**:

* CLI
  * Updated the mTLS trust anchor checks to eliminate false positives caused by
    extra trailing spaces
  * Reduced the severity level of the Linkerd version checks, so that they
    don't fail when the external version endpoint is unreachable
    (thanks @mayankshah1607!)
  * Added a new `tap` APIService check to aid with uncovering Kubernetes API
    aggregatation layer issues (thanks @droidnoob!)
  * Introduced CNI checks to confirm the CNI plugin is installed and ready;
    this is done through `linkerd check --pre --linkerd-cni-enabled` before
    installation and `linkerd check` after installation if the CNI plugin is
    present
  * Added support for the `--as-group` flag so that users can impersonate
    groups for Kubernetes operations (thanks @mayankshah1607!)
  * Added HA specific checks to `linkerd check` to ensure that the `kube-system`
    namespace has the `config.linkerd.io/admission-webhooks:disabled`
    label set
  * Fixed a problem causing the presence of unnecessary empty fields in
    generated resource definitions (thanks @mayankshah1607)
  * Added the ability to pass both port numbers and port ranges to
    `--skip-inbound-ports` and `--skip-outbound-ports` (thanks to @javaducky!)
  * Increased the comprehensiveness of `linkerd check --pre`
  * Added TLS certificate validation to `check` and `upgrade` commands
  * Added support for injecting CronJobs and ReplicaSets, as well as the ability
    to use them as targets in the CLI subcommands
  * Introduced the new flags `--identity-issuer-certificate-file`,
    `--identity-issuer-key-file` and `identity-trust-anchors-file` to `linkerd
    upgrade` to support trust anchor and issuer certificate rotation
  * Added a check that ensures using `--namespace` and `--all-namespaces`
    results in an error as they are mutually exclusive
  * Added a `Dashboard.Replicas` parameter to the Linkerd Helm chart to allow
    configuring the number of dashboard replicas (thanks @KIVagant!)
  * Removed redundant service profile check (thanks @alenkacz!)
  * Updated `uninject` command to work with namespace resources
    (thanks @mayankshah1607!)
  * Added a new `--identity-external-issuer` flag to `linkerd install` that
    configures Linkerd to use certificates issued by an external certificate
    issuer (such as `cert-manager`)
  * Added support for injecting a namespace to `linkerd inject` (thanks
    @mayankshah1607!)
  * Added checks to `linkerd check --preinstall` ensuring Kubernetes Secrets
    can be created and accessed
  * Fixed `linkerd tap` sometimes displaying incorrect pod names for unmeshed
    IPs that match multiple running pods
  * Made `linkerd install --ignore-cluster` and `--skip-checks` faster
  * Fixed a bug causing `linkerd upgrade` to fail when used with
  `--from-manifest`
  * Made `--cluster-domain` an install-only flag (thanks @bmcstdio!)
  * Updated `check` to ensure that proxy trust anchors match configuration
       (thanks @ereslibre!)
  * Added condition to the `linkerd stat` command that requires a window size
    of at least 15 seconds to work properly with Prometheus
* Controller
  * Fixed an issue where an override of the Docker registry was not being
    applied to debug containers (thanks @javaducky!)
  * Added check for the Subject Alternate Name attributes to the API server
    when access restrictions have been enabled (thanks @javaducky!)
  * Added support for arbitrary pod labels so that users can leverage the
    Linkerd provided Prometheus instance to scrape for their own labels
    (thanks @daxmc99!)
  * Fixed an issue with CNI config parsing
  * Fixed a race condition in the `linkerd-web` service
  * Updated Prometheus to 2.15.2 (thanks @Pothulapati)
  * Increased minimum kubernetes version to 1.13.0
  * Added support for pod ip and service cluster ip lookups in the destination
    service
  * Added recommended kubernetes labels to control-plane
  * Added the `--wait-before-exit-seconds` flag to linkerd inject for the proxy
    sidecar to delay the start of its shutdown process (a huge commit from
    @KIVagant, thanks!)
  * Added a pre-sign check to the identity service
  * Fixed inject failures for pods with security context capabilities
  * Added `conntrack` to the `debug` container to help with connection tracking
    debugging
  * Fixed a bug in `tap` where mismatch cluster domain and trust domain caused
    `tap` to hang
  * Fixed an issue in the `identity` RBAC resource which caused start up errors
    in k8s 1.6 (thanks @Pothulapati!)
  * Added support for using trust anchors from an external certificate issuer
    (such as `cert-mananger`) to the `linkerd-identity` service
  * Added support for headless services (thanks @JohannesEH!)
* Helm
  * **Breaking change**: Renamed `noInitContainer` parameter to `cniEnabled`
  * **Breaking Change** Updated Helm charts to follow best practices (thanks
    @Pothulapati and @javaducky!)
  * Fixed an issue with `helm install` where the lists of ignored inbound and
    outbound ports would not be reflected
  * Fixed the `linkerd-cni` Helm chart not setting proper namespace annotations
    and labels
  * Fixed certificate issuance lifetime not being set when installing through
    Helm
  * Updated the helm build to retain previous releases
  * Moved CNI template into its own Helm chart
* Proxy
  * Fixed an issue that could cause the OpenCensus exporter to stall
  * Improved error classification and error responses for gRPC services
  * Fixed a bug where the proxy could stop receiving service discovery updates,
    resulting in 503 errors
  * Improved debug/error logging to include detailed contextual information
  * Fixed a bug in the proxy's logging subsystem that could cause the proxy to
    consume memory until the process is OOM killed, especially when the proxy was
    configured to log diagnostic information
  * Updated proxy dependencies to address RUSTSEC-2019-0033, RUSTSEC-2019-0034,
    and RUSTSEC-2020-02
* Web UI
  * Fixed an error when refreshing an already open dashboard when the Linkerd
    version has changed
  * Increased the speed of the dashboard by pausing network activity when the
    dashboard is not visible to the user
  * Added support for CronJobs and ReplicaSets, including new Grafana dashboards
    for them
  * Added `linkerd check` to the dashboard in the `/controlplane` view
  * Added request and response headers to the `tap` expanded view in the
    dashboard
  * Added filter to namespace select button
  * Improved how empty tables are displayed
  * Added `Host:` header validation to the `linkerd-web` service, to protect
    against DNS rebinding attacks
  * Made the dashboard sidebar component responsive
  * Changed the navigation bar color to the one used on the [Linkerd](https://linkerd.io/) website
* Internal
  * Added validation to incoming sidecar injection requests that ensures
    the value of `linkerd.io/inject` is either `enabled` or `disabled`
    (thanks @mayankshah1607)
  * Upgraded the Prometheus Go client library to v1.2.1 (thanks @daxmc99!)
  * Fixed an issue causing `tap`, `injector` and `sp-validator` to use
    old certificates after `helm upgrade` due to not being restarted
  * Fixed incomplete Swagger definition of the tap api, causing benign
    error logging in the kube-apiserver
  * Removed the destination container from the linkerd-controller deployment as
    it now runs in the linkerd-destination deployment
  * Allowed the control plane to be injected with the `debug` container
  * Updated proxy image build script to support HTTP proxy options
    (thanks @joakimr-axis!)
  * Updated the CLI `doc` command to auto-generate documentation for the proxy
    configuration annotations (thanks @StupidScience!)
  * Added new `--trace-collector` and `--trace-collector-svc-account` flags to
    `linkerd inject` that configures the OpenCensus trace collector used by
    proxies in the injected workload (thanks @Pothulapati!)
  * Added a new `--control-plane-tracing` flag to `linkerd install` that enables
    distributed tracing in the control plane (thanks @Pothulapati!)
  * Added distributed tracing support to the control plane (thanks
    @Pothulapati!)

## edge-20.2.1

This edge release is a release candidate for `stable-2.7` and fixes an issue
where the proxy could consume inappropriate amounts of memory.

* Proxy
  * Fixed a bug in the proxy's logging subsystem that could cause the proxy to
    consume memory until the process is OOM killed, especially when the proxy was
    configured to log diagnostic information
  * Fixed properly emitting `grpc-status` headers when signaling proxy errors to
    gRPC clients
  * Updated certain proxy dependencies to address RUSTSEC-2019-0033,
    RUSTSEC-2019-0034, and RUSTSEC-2020-02

## edge-20.1.4

This edge release is a release candidate for `stable-2.7`.

The `linkerd check` command has been updated to improve the control plane
debugging experience.

* CLI
  * Updated the mTLS trust anchor checks to eliminate false positives caused by
    extra trailing spaces
  * Reduced the severity level of the Linkerd version checks, so that they
    don't fail when the external version endpoint is unreachable
    (thanks @mayankshah1607!)
  * Added a new `tap` APIService check to aid with uncovering Kubernetes API
    aggregatation layer issues (thanks @droidnoob!)

## edge-20.1.3

This edge release is a release candidate for `stable-2.7`.

An update to the Helm charts has caused a **breaking change** for users who
have installed Linkerd using Helm. In order to make the purpose of the
`noInitContainer` parameter more explicit, it has been renamed to `cniEnabled`.

* CLI
  * Introduced CNI checks to confirm the CNI plugin is installed and ready;
    this is done through `linkerd check --pre --linkerd-cni-enabled` before
    installation and `linkerd check` after installation if the CNI plugin is
    present
  * Added support for the `--as-group` flag so that users can impersonate
    groups for Kubernetes operations (thanks @mayankshah160!)
* Controller
  * Fixed an issue where an override of the Docker registry was not being
    applied to debug containers (thanks @javaducky!)
  * Added check for the Subject Alternate Name attributes to the API server
    when access restrictions have been enabled (thanks @javaducky!)
  * Added support for arbitrary pod labels so that users can leverage the
    Linkerd provided Prometheus instance to scrape for their own labels
    (thanks @daxmc99!)
  * Fixed an issue with CNI config parsing
* Helm
  * **Breaking change**: Renamed `noInitContainer` parameter to `cniEnabled`
  * Fixed an issue with `helm install` where the lists of ignored inbound and
    outbound ports would not be reflected

## edge-20.1.2

* CLI
  * Added HA specific checks to `linkerd check` to ensure that the `kube-system`
    namespace has the `config.linkerd.io/admission-webhooks:disabled`
    label set
  * Fixed a problem causing the presence of unnecessary empty fields in
    generated resource definitions (thanks @mayankshah1607)
* Proxy
  * Fixed an issue that could cause the OpenCensus exporter to stall
* Internal
  * Added validation to incoming sidecar injection requests that ensures
    the value of `linkerd.io/inject` is either `enabled` or `disabled`
    (thanks @mayankshah1607)

## edge-20.1.1

This edge release includes experimental improvements to the Linkerd proxy's
request buffering and backpressure infrastructure.

Additionally, we've fixed several bugs when installing Linkerd with Helm,
updated the CLI to allow using both port numbers _and_ port ranges with the
`--skip-inbound-ports` and `--skip-outbound-ports`  flags, and fixed a dashboard
error that can occur if the dashboard is open in a browser while updating Linkerd.

**Note**: The `linkerd-proxy` version included with this release is more
experimental than usual. We'd love your help testing, but be aware that there
might be stability issues.

* CLI
  * Added the ability to pass both port numbers and port ranges to
    `--skip-inbound-ports` and `--skip-outbound-ports` (thanks to @javaducky!)
* Controller
  * Fixed a race condition in the `linkerd-web` service
  * Updated Prometheus to 2.15.2 (thanks @Pothulapati)
* Web UI
  * Fixed an error when refreshing an already open dashboard when the Linkerd
    version has changed
* Proxy
  * Internal changes to the proxy's request buffering and backpressure
    infrastructure
* Helm
  * Fixed the `linkerd-cni` Helm chart not setting proper namespace annotations
    and labels
  * Fixed certificate issuance lifetime not being set when installing through
    Helm
  * More improvements to Helm best practices (thanks to @Pothulapati!)

## edge-19.12.3

This edge release adds support for pod IP and service cluster IP lookups,
improves performance of the dashboard, and makes `linkerd check --pre` perform
more comprehensive checks.

The `--wait-before-exit-seconds` flag has been added to allow Linkerd users to
 opt in
to `preStop hooks`. The details of this change are in
[#3798](https://github.com/linkerd/linkerd2/pull/3798).

Also, the proxy has been updated to `v2.82.0` which improves gRPC error
classification and
[ensures that resolutions](https://github.com/linkerd/linkerd2/pull/3848) are
released when the associated balancer becomes idle.

Finally, an update to follow best practices in the Helm charts has caused a
*breaking change*. Users who have installed Linkerd using Helm must be
certain to read the details of
[#3822](https://github.com/linkerd/linkerd2/issues/3822)

* CLI
  * Increased the comprehensiveness of `linkerd check --pre`
  * Added TLS certificate validation to `check` and `upgrade` commands
* Controller
  * Increased minimum kubernetes version to 1.13.0
  * Added support for pod ip and service cluster ip lookups in the destination
    service
  * Added recommended kubernetes labels to control-plane
  * Added the `--wait-before-exit-seconds` flag to linkerd inject for the proxy
    sidecar to delay the start of its shutdown process (a huge commit from
    @KIVagant, thanks!)
  * Added a pre-sign check to the identity service
* Web UI
  * Increased the speed of the dashboard by pausing network activity when the
    dashboard is not visible to the user
* Proxy
  * Added a timeout to release resolutions to idle balancers
  * Improved error classification for gRPC services
* Internal
  * **Breaking Change** Updated Helm charts to follow best practices using
    proper casing (thanks @Pothulapati!)

## edge-19.12.2

* CLI
  * Added support for injecting CronJobs and ReplicaSets, as well as the ability
    to use them as targets in the CLI subcommands
  * Introduced the new flags `--identity-issuer-certificate-file`,
    `--identity-issuer-key-file` and `identity-trust-anchors-file` to `linkerd
    upgrade` to support trust anchor and issuer certificate rotation
* Controller
  * Fixed inject failures for pods with security context capabilities
* Web UI
  * Added support for CronJobs and ReplicaSets, including new Grafana dashboards
    for them
* Proxy
  * Fixed a bug where the proxy could stop receiving service discovery updates,
    resulting in 503 errors
* Internal
  * Moved CNI template into a Helm chart to prepare for future publication
  * Upgraded the Prometheus Go client library to v1.2.1 (thanks @daxmc99!)
  * Reenabled certificates rotation integration tests

## edge-19.12.1

* CLI
  * Added condition to the `linkerd stat` command that requires a window size
    of at least 15 seconds to work properly with Prometheus
* Internal
  * Fixed whitespace path handling in non-docker build scripts (thanks
    @joakimr-axis!)
  * Removed Calico logutils dependency that was incompatible with Go 1.13
  * Updated Helm templates to use fully-qualified variable references based
    upon Helm best practices (thanks @javaducky!)

## edge-19.11.3

* CLI
  * Added a check that ensures using `--namespace` and `--all-namespaces`
    results in an error as they are mutually exclusive
* Internal
  * Fixed an issue causing `tap`, `injector` and `sp-validator` to use
    old certificates after `helm upgrade` due to not being restarted
  * Fixed incomplete Swagger definition of the tap api, causing benign
    error logging in the kube-apiserver

## edge-19.11.2

* CLI
  * Added a `Dashboard.Replicas` parameter to the Linkerd Helm chart to allow
    configuring the number of dashboard replicas (thanks @KIVagant!)
  * Removed redundant service profile check (thanks @alenkacz!)
* Web UI
  * Added `linkerd check` to the dashboard in the `/controlplane` view
  * Added request and response headers to the `tap` expanded view in the
    dashboard
* Internal
  * Removed the destination container from the linkerd-controller deployment as
    it now runs in the linkerd-destination deployment
  * Upgraded Go to version 1.13.4

## edge-19.11.1

* CLI
  * Updated `uninject` command to work with namespace resources
    (thanks @mayankshah1607!)
* Controller
  * Added `conntrack` to the `debug` container to help with connection tracking
    debugging
  * Fixed a bug in `tap` where mismatch cluster domain and trust domain caused
    `tap` to hang
  * Fixed an issue in the `identity` RBAC resource which caused start up errors
    in k8s 1.6 (thanks @Pothulapati!)
* Proxy
  * Improved debug/error logging to include detailed contextual information
* Web UI
  * Added filter to namespace select button
  * Improved how empty tables are displayed
* Internal
  * Added integration test for custom cluster domain
  * Allowed the control plane to be injected with the `debug` container
  * Updated proxy image build script to support HTTP proxy options
    (thanks @joakimr-axis!)
  * Updated the CLI `doc` command to auto-generate documentation for the proxy
    configuration annotations (thanks @StupidScience!)

## edge-19.10.5

This edge release adds support for integrating Linkerd's PKI with an external
certificate issuer such as [`cert-manager`], adds distributed tracing support to
the Linkerd control plane, and adds protection against DNS rebinding attacks to
the web dashboard. In addition, it includes several improvements to the Linkerd
CLI.

* CLI
  * Added a new `--identity-external-issuer` flag to `linkerd install` that
    configures Linkerd to use certificates issued by an external certificate
    issuer (such as `cert-manager`)
  * Added support for injecting a namespace to `linkerd inject` (thanks
    @mayankshah1607!)
  * Added checks to `linkerd check --preinstall` ensuring Kubernetes Secrets
    can be created and accessed
  * Fixed `linkerd tap` sometimes displaying incorrect pod names for unmeshed
    IPs that match multiple running pods
* Controller
  * Added support for using trust anchors from an external certificate issuer
    (such as `cert-mananger`) to the `linkerd-identity` service
* Web UI
  * Added `Host:` header validation to the `linkerd-web` service, to protect
    against DNS rebinding attacks
* Internal
  * Added new `--trace-collector` and `--trace-collector-svc-account` flags to
    `linkerd inject` that configures the OpenCensus trace collector used by
    proxies in the injected workload (thanks @Pothulapati!)
  * Added a new `--control-plane-tracing` flag to `linkerd install` that enables
    distributed tracing in the control plane (thanks @Pothulapati!)
  * Added distributed tracing support to the control plane (thanks
    @Pothulapati!)

Also, thanks to @joakimr-axis for several fixes and improvements to internal
build scripts!

[`cert-manager`]: https://github.com/jetstack/cert-manager

## edge-19.10.4

This edge release adds dashboard UX enhancements, and improves the speed of the CLI.

* CLI
  * Made `linkerd install --ignore-cluster` and `--skip-checks` faster
  * Fixed a bug causing `linkerd upgrade` to fail when used with
  `--from-manifest`
* Web UI
  * Made the dashboard sidebar component responsive
  * Changed the navigation bar color to the one used on the [Linkerd](https://linkerd.io/) website

## edge-19.10.3

This edge release adds support for headless services, improves the upgrade
process after installing Linkerd with a custom cluster domain, and enhances
the `check` functionality to report invalid trust anchors.

* CLI
  * Made `--cluster-domain` an install-only flag (thanks @bmcstdio!)
  * Updated `check` to ensure that proxy trust anchors match configuration
       (thanks @ereslibre!)
* Controller
  * Added support for headless services (thanks @JohannesEH!)
* Helm
  * Updated the helm build to retain previous releases

## stable-2.6.0

This release introduces distributed tracing support, adds request and response
headers to `linkerd tap`, dramatically improves the performance of the dashboard
on large clusters, adds traffic split visualizations to the dashboard, adds a
public Helm repo, and many more improvements!

For more details, see the announcement blog post:
https://linkerd.io/2019/10/10/announcing-linkerd-2.6/

To install this release, run: `curl https://run.linkerd.io/install | sh`

**Upgrade notes**: Please see the [upgrade
instructions](https://linkerd.io/2/tasks/upgrade/#upgrade-notice-stable-2-6-0).

**Special thanks to**: @alenkacz, @arminbuerkle, @bmcstdio, @bourquep,
@brianstorti, @kevtaylor, @KIVagant, @pierDipi, and @Pothulapati!

**Full release notes**:

* CLI
  * Added a new `json` output option to the `linkerd tap` command, which exposes
    request and response headers
  * Added a public Helm repo - for full installation instructions, see our [Helm
    documentation](https://linkerd.io/2/tasks/install-helm/).
  * Added an `--address` flag to `linkerd dashboard`, allowing users to specify
    a port-forwarding address (thanks @bmcstdio!)
  * Added node selector constraints to Helm installation, so users can control
    which nodes the control plane is deployed to (thanks @bmcstdio!)
  * Added a `--cluster-domain` flag to the `linkerd install` command that allows
    setting a custom cluster domain (thanks @arminbuerkle!)
  * Added a `--disable-heartbeat` flag for `linkerd install | upgrade` commands
  * Allowed disabling namespace creation when installing Linkerd using Helm
    (thanks @KIVagant!)
  * Improved the error message when the CLI cannot connect to Kubernetes (thanks
    @alenkacz!)
* Controller
  * Updated the Prometheus config to keep only needed `cadvisor` metrics,
    substantially reducing the number of time-series stored in most clusters
  * Introduced `config.linkerd.io/trace-collector` and
    `config.alpha.linkerd.io/trace-collector-service-account` pod spec
    annotations to support per-pod tracing
  * Instrumented the proxy injector to provide additional metrics about
    injection (thanks @Pothulapati!)
  * Added Kubernetes events (and log lines) when the proxy injector injects a
    deployment, and when injection is skipped
  * Fixed a workload admission error between the Kubernetes apiserver and the HA
    proxy injector, by allowing workloads in a namespace to be omitted from the
    admission webhooks phase using the `config.linkerd.io/admission-webhooks:
    disabled` label (thanks @hasheddan!)
  * Fixed proxy injector timeout during a large number of concurrent injections
  * Added support for disabling the heartbeat cronjob (thanks @kevtaylor!)
* Proxy
  * Added distributed tracing support
  * Decreased proxy Docker image size by removing bundled debug tools
  * Added 587 (SMTP) to the list of ports to ignore in protocol detection (bound
    to server-speaks-first protocols) (thanks @brianstorti!)
* Web UI
  * Redesigned dashboard navigation so workloads are now viewed by namespace,
    with an "All Namespaces" option, in order to increase dashboard speed
  * Added Traffic Splits as a resource to the dashboard, including a Traffic
    Split detail page
  * Added a `Linkerd Namespace` Grafana dashboard, allowing users to view
    historical data for a given namespace, similar to CLI output for `linkerd
    stat deploy -n myNs` (thanks @bourquep!)
  * Fixed bad request in the top routes tab on empty fields (thanks @pierDipi!)
* Internal
  * Moved CI from Travis to GitHub Actions
  * Added requirement for Go `1.12.9` for controller builds to include security
    fixes
  * Added support for Kubernetes `1.16`
  * Upgraded client-go to `v12.0.0`

## edge-19.10.2

This edge release is a release candidate for `stable-2.6`.

* Controller
  * Added the destination container back to the controller; it had previously
    been separated into its own deployment. This ensures backwards compatibility
    and allows users to avoid data plane downtime during an upcoming upgrade to
    `stable-2.6`.

## edge-19.10.1

This edge release is a release candidate for `stable-2.6`.

* Proxy
  * Improved error logging when the proxy fails to emit trace spans
  * Fixed bug in distributed tracing where trace ids with fewer than 16 bytes
    were discarded
* Internal
  * Added integration tests for `linkerd edges` and `linkerd endpoints`

## edge-19.9.5

This edge release is a release candidate for `stable-2.6`.

* Helm
  * Added node selector constraints, so users can control which nodes the
    control plane is deployed to (thanks @bmcstdio!)
* CLI
  * Added request and response headers to the JSON output option for `linkerd
    tap`

## edge-19.9.4

This edge release introduces experimental support for distributed tracing as
well as a redesigned sidebar in the Web UI!

Experimental support for distributed tracing means that Linkerd data plane
proxies can now emit trace spans, allowing you to see the exact amount of time
spent in the Linkerd proxy for traced requests. The new
`config.linkerd.io/trace-collector` and
`config.alpha.linkerd.io/trace-collector-service-account` tracing annotations
allow specifying which pods should emit trace spans.

The goal of the dashboard's sidebar redesign was to reduce load on Prometheus
and simplify navigation by providing top-level views centered around namespaces
and workloads.

* CLI
  * Introduced a new `--cluster-domain` flag to the `linkerd install` command
    that allows setting a custom cluster domain (thanks @arminbuerkle!)
  * Fixed the `linkerd endpoints` command to use the correct Destination API
    address (thanks @Pothulapati!)
  * Added `--disable-heartbeat` flag for `linkerd` `install|upgrade` commands
* Controller
  * Instrumented the proxy-injector to provide additional metrics about
    injection (thanks @Pothulapati!)
  * Added support for `config.linkerd.io/admission-webhooks: disabled` label on
    namespaces so that the pods creation events in these namespaces are ignored
    by the proxy injector; this fixes situations in HA deployments where the
    proxy-injector is installed in `kube-system` (thanks @hasheddan!)
  * Introduced `config.linkerd.io/trace-collector` and
    `config.alpha.linkerd.io/trace-collector-service-account` pod spec
    annotations to support per-pod tracing
* Web UI
  * Workloads are now viewed by namespace, with an "All Namespaces" option, to
    improve dashboard performance
* Proxy
  * Added experimental distributed tracing support

## edge-19.9.3

* Helm
  * Allowed disabling namespace creation during install (thanks @KIVagant!)
* CLI
  * Added a new `json` output option to the `linkerd tap` command
* Controller
  * Fixed proxy injector timeout during a large number of concurrent injections
  * Separated the destination controller into its own separate deployment
  * Updated Prometheus config to keep only needed `cadvisor` metrics,
    substantially reducing the number of time-series stored in most clusters
* Web UI
  * Fixed bad request in the top routes tab on empty fields (thanks @pierDipi!)
* Proxy
  * Fixes to the client's backoff logic
  * Added 587 (SMTP) to the list of ports to ignore in protocol detection (bound
    to server-speaks-first protocols) (thanks @brianstorti!)

## edge-19.9.2

Much of our effort has been focused on improving our build and test
infrastructure, but this edge release lays the groundwork for some big
new features to land in the coming releases!

* Helm
  * There's now a public Helm repo! This release can be installed with:
   `helm repo add linkerd-edge https://helm.linkerd.io/edge && helm install linkerd-edge/linkerd2`
  * Improved TLS credential parsing by ignoring spurious newlines
* Proxy
  * Decreased proxy-init Docker image size by removing bundled debug tools
* Web UI
  * Fixed an issue where the edges table could end up with duplicates
  * Added an icon to more clearly label external links
* Internal
  * Upgraded client-go to v12.0.0
  * Moved CI from Travis to GitHub Actions

## edge-19.9.1

This edge release adds traffic splits into the Linkerd dashboard as well as a
variety of other improvements.

* CLI
  * Improved the error message when the CLI cannot connect to Kubernetes (thanks
    @alenkacz!)
  * Added `--address` flag to `linkerd dashboard` (thanks @bmcstdio!)
* Controller
  * Fixed an issue where the proxy-injector had insufficient RBAC permissions
  * Added support for disabling the heartbeat cronjob (thanks @kevtaylor!)
* Proxy
  * Decreased proxy Docker image size by removing bundled debug tools
  * Fixed an issue where the incorrect content-length could be set for GET
    requests with bodies
* Web UI
  * Added trafficsplits as a resource to the dashboard, including a trafficsplit
    detail page
* Internal
  * Added support for Kubernetes 1.16

## edge-19.8.7

* Controller
  * Added Kubernetes events (and log lines) when the proxy injector injects a
    deployment, and when injection is skipped
  * Additional preparation for configuring the cluster base domain (thanks
    @arminbuerkle!)
* Proxy
  * Changed the proxy to require the `LINKERD2_PROXY_DESTINATION_SVC_ADDR`
    environment variable when starting up
* Web UI
  * Increased dashboard speed by consolidating existing Prometheus queries

## edge-19.8.6

A new Grafana dashboard has been added which shows historical data for a
selected namespace. The build process for controller components now requires
`Go 1.12.9`. Additional contributions were made towards support for custom
cluster domains.

* Web UI
  * Added a `Linkerd Namespace` Grafana dashboard, allowing users to view
    historical data for a given namespace, similar to CLI output for
    `linkerd stat deploy -n myNs` (thanks @bourquep!)
* Internal
  * Added requirement for Go `1.12.9` for controller builds to include
    security fixes
  * Set `LINKERD2_PROXY_DESTINATION_GET_SUFFIXES` proxy environment variable,
    in preparation for custom cluster domain support (thanks @arminbuerkle!)

## stable-2.5.0

This release adds [Helm support](https://linkerd.io/2/tasks/install-helm/),
[tap authentication and authorization via RBAC](https://linkerd.io/tap-rbac),
traffic split stats, dynamic logging levels, a new cluster monitoring dashboard,
and countless performance enhancements and bug fixes.

For more details, see the announcement blog post:
https://linkerd.io/2019/08/20/announcing-linkerd-2.5/

To install this release, run: `curl https://run.linkerd.io/install | sh`

**Upgrade notes**: Use the `linkerd upgrade` command to upgrade the control
plane. This command ensures that all existing control plane's configuration and
mTLS secrets are retained. For more details, please see the [upgrade
instructions](https://linkerd.io/2/tasks/upgrade/#upgrade-notice-stable-2-5-0).

**Special thanks to**: @alenkacz, @codeman9, @ethan-daocloud, @jonathanbeber,
and @Pothulapati!

**Full release notes**:

* CLI
  * **New** Updated `linkerd tap`, `linkerd top` and `linkerd profile --tap` to
    require `tap.linkerd.io` RBAC privileges. See https://linkerd.io/tap-rbac
    for more info
  * **New** Added traffic split metrics via `linkerd stat trafficsplits`
    subcommand
  * Made the `linkerd routes` command traffic split aware
  * Introduced the `linkerd --as` flag which allows users to impersonate another
    user for Kubernetes operations
  * Introduced the `--all-namespaces` (`-A`) option to the `linkerd get`,
    `linkerd edges` and `linkerd stat` commands to retrieve resources across
    all namespaces
  * Improved the installation report produced by the `linkerd check` command
    to include the control plane pods' live status
  * Fixed bug in the `linkerd upgrade config` command that was causing it to
    crash
  * Introduced `--use-wait-flag` to the `linkerd install-cni` command, to
    configure the CNI plugin to use the `-w` flag for `iptables` commands
  * Introduced `--restrict-dashboard-privileges` flag to `linkerd install`
    command, to disallow tap in the dashboard
  * Fixed `linkerd uninject` not removing `linkerd.io/inject: enabled`
    annotations
  * Fixed `linkerd stat -h` example commands (thanks @ethan-daocloud!)
  * Fixed incorrect "meshed" count in `linkerd stat` when resources share the
    same label selector for pods (thanks @jonathanbeber!)
  * Added pod status to the output of the `linkerd stat` command (thanks
    @jonathanbeber!)
  * Added namespace information to the `linkerd edges` command output and a new
    `-o wide` flag that shows the identity of the client and server if known
  * Added a check to the `linkerd check` command to validate the user has
    privileges necessary to create CronJobs
  * Added a new check to the `linkerd check --pre` command validating that if
    PSP is enabled, the NET_RAW capability is available
* Controller
  * **New** Disabled all unauthenticated tap endpoints. Tap requests now require
    [RBAC authentication and authorization](https://linkerd.io/tap-rbac)
  * The `l5d-require-id` header is now set on tap requests so that a connection
    is established over TLS
  * Introduced a new RoleBinding in the `kube-system` namespace to provide
    [access to tap](https://linkerd.io/tap-rbac)
  * Added HTTP security headers on all dashboard responses
  * Added support for namespace-level proxy override annotations (thanks
    @Pothulapati!)
  * Added resource limits when HA is enabled (thanks @Pothulapati!)
  * Added pod anti-affinity rules to the control plane pods when HA is enabled
    (thanks @Pothulapati!)
  * Fixed a crash in the destination service when an endpoint does not have a
    `TargetRef`
  * Updated the destination service to return `InvalidArgument` for external
    name services so that the proxy does not immediately fail the request
  * Fixed an issue with discovering StatefulSet pods via their unique hostname
  * Fixed an issue with traffic split where outbound proxy stats are missing
  * Upgraded the service profile CRD to v1alpha2. No changes required for users
    currently using v1alpha1
  * Updated the control plane's pod security policy to restrict workloads from
    running as `root` in the CNI mode (thanks @codeman9!)
  * Introduced optional cluster heartbeat cron job
  * Bumped Prometheus to 2.11.1
  * Bumped Grafana to 6.2.5
* Proxy
  * **New** Added a new `/proxy-log-level` endpoint to update the log level at
    runtime
  * **New** Updated the tap server to only admit requests from the control
    plane's tap controller
  * Added `request_handle_us` histogram to measure proxy overhead
  * Fixed gRPC client cancellations getting recorded as failures rather than
    as successful
  * Fixed a bug where tap would stop streaming after a short amount of time
  * Fixed a bug that could cause the proxy to leak service discovery resolutions
    to the Destination controller
* Web UI
  * **New** Added "Kubernetes cluster monitoring" Grafana dashboard with cluster
    and containers metrics
  * Updated the web server to use the new tap APIService. If the `linkerd-web`
    service account is not authorized to tap resources, users will see a link to
    documentation to remedy the error

## edge-19.8.5

This edge release is a release candidate for `stable-2.5`.

* CLI
  * Fixed CLI filepath issue on Windows
* Proxy
  * Fixed gRPC client cancellations getting recorded as failures rather than
    as successful

## edge-19.8.4

This edge release is a release candidate for `stable-2.5`.

* CLI
  * Introduced `--use-wait-flag` to the `linkerd install-cni` command, to
    configure the CNI plugin to use the `-w` flag for `iptables` commands
* Controller
  * Disabled the tap gRPC server listener. All tap requests now require RBAC
    authentication and authorization

## edge-19.8.3

This edge release introduces a new `linkerd stat trafficsplits` subcommand, to
show traffic split metrics. It also introduces a "Kubernetes cluster monitoring"
Grafana dashboard.

* CLI
  * Added traffic split metrics via `linkerd stat trafficsplits` subcommand
  * Fixed `linkerd uninject` not removing `linkerd.io/inject: enabled`
    annotations
  * Fixed `linkerd stat -h` example commands (thanks @ethan-daocloud!)
* Controller
  * Added support for namespace-level proxy override annotations
  * Removed unauthenticated tap from the Public API
* Proxy
  * Added `request_handle_us` histogram to measure proxy overhead
  * Updated the tap server to only admit requests from the control plane's tap
    controller
  * Fixed a bug where tap would stop streaming after a short amount of time
  * Fixed a bug that could cause the proxy to leak service discovery resolutions
    to the Destination controller
* Web UI
  * Added "Kubernetes cluster monitoring" Grafana dashboard with cluster and
    containers metrics
* Internal
  * Updated `linkerd install` and `linkerd upgrade` to use Helm charts for
    templating
  * Pinned Helm tooling to `v2.14.3`
  * Added Helm integration tests
  * Added container CPU and memory usage to `linkerd-heartbeat` requests
  * Removed unused inject code (thanks @alenkacz!)

## edge-19.8.2

This edge release introduces the new Linkerd control plane Helm chart, named
`linkerd2`. Helm users can now install and remove the Linkerd control plane by
using the `helm install` and `helm delete` commands. Proxy injection also now
uses Helm charts.

No changes were made to the existing `linkerd install` behavior.

For detailed installation steps using Helm, see the notes for [PR
#3146](https://github.com/linkerd/linkerd2/pull/3146).

* CLI
  * Updated `linkerd top` and `linkerd profile --tap` to require
    `tap.linkerd.io` RBAC privileges, see https://linkerd.io/tap-rbac for more
    info
  * Modified `tap.linkerd.io` APIService to enable usage in `kubectl auth can-i`
    commands
  * Introduced `--restrict-dashboard-privileges` flag to `linkerd install`
    command, to restrict the dashboard's default privileges to disallow tap
* Controller
  * Introduced a new ClusterRole, `linkerd-linkerd-tap-admin`, which gives
    cluster-wide tap privileges. Also introduced a new ClusterRoleBinding,
    `linkerd-linkerd-web-admin`, which binds the `linkerd-web` service account
    to the new tap ClusterRole
  * Removed successfully completed `linkerd-heartbeat` jobs from pod listing in
    the linkerd control plane to streamline `get po` output (thanks
    @Pothulapati!)
* Web UI
  * Updated the web server to use the new tap APIService. If the `linkerd-web`
    service account is not authorized to tap resources, users will see a link to
    documentation to remedy the error

## edge-19.8.1

**Significant Update**

This edge release introduces a new tap APIService. The Kubernetes apiserver
authenticates the requesting tap user and then forwards tap requests to the new
tap APIServer. The `linkerd tap` command now makes requests against the
APIService.

With this release, users must be authorized via RBAC to use the `linkerd tap`
command. Specifically `linkerd tap` requires the `watch` verb on all resources
in the `tap.linkerd.io/v1alpha1` APIGroup. More granular access is also
available via sub-resources such as `deployments/tap` and `pods/tap`.

* CLI
  * Added a check to the `linkerd check` command to validate the user has
    privileges necessary to create CronJobs
  * Introduced the `linkerd --as` flag which allows users to impersonate another
    user for Kubernetes operations
  * The `linkerd tap` command now makes requests against the tap APIService
* Controller
  * Added HTTP security headers on all dashboard responses
  * Fixed nil pointer dereference in the destination service when an endpoint
    does not have a `TargetRef`
  * Added resource limits when HA is enabled
  * Added RSA support to TLS libraries
  * Updated the destination service to return `InvalidArgument` for external
    name services so that the proxy does not immediately fail the request
  * The `l5d-require-id` header is now set on tap requests so that a connection
    is established over TLS
  * Introduced the `APIService/v1alpha1.tap.linkerd.io` global resource
  * Introduced the `ClusterRoleBinding/linkerd-linkerd-tap-auth-delegator`
    global resource
  * Introduced the `Secret/linkerd-tap-tls` resource into the `linkerd`
    namespace
  * Introduced the `RoleBinding/linkerd-linkerd-tap-auth-reader` resource into
    the `kube-system` namespace
* Proxy
  * Added the `LINKERD2_PROXY_TAP_SVC_NAME` environment variable so that the tap
    server attempts to authorize client identities
* Internal
  * Replaced `dep` with Go modules for dependency management

## edge-19.7.5

* CLI
  * Improved the installation report produced by the `linkerd check` command
    to include the control plane pods' live status
  * Added the `--all-namespaces` (`-A`) option to the `linkerd get`,
    `linkerd edges` and `linkerd stat` commands to retrieve resources across
    all namespaces
* Controller
  * Fixed an issue with discovering StatefulSet pods via their unique hostname
  * Fixed an issue with traffic split where outbound proxy stats are missing
  * Bumped Prometheus to 2.11.1
  * Bumped Grafana to 6.2.5
  * Upgraded the service profile CRD to v1alpha2 where the openAPIV3Schema
    validation is replaced by a validating admission webhook. No changes
    required for users currently using v1alpha1
  * Updated the control plane's pod security policy to restrict workloads from
    running as `root` in the CNI mode (thanks @codeman9!)
  * Introduced cluster heartbeat cron job
* Proxy
  * Introduced the `l5d-require-id` header to enforce TLS outbound
    communication from the Tap server

## edge-19.7.4

* CLI
  * Made the `linkerd routes` command traffic-split aware
  * Fixed bug in the `linkerd upgrade config` command that was causing it to
    crash
  * Added pod status to the output of the `linkerd stat`command (thanks
    @jonathanbeber!)
  * Fixed incorrect "meshed" count in `linkerd stat` when resources share the
    same label selector for pods (thanks @jonathanbeber!)
  * Added namespace information to the `linkerd edges` command output and a new
    `-o wide` flag that shows the identity of the client and server if known
  * Added a new check to the `linkerd check --pre` command validating that if
    PSP is enabled, the NET_RAW capability is available
* Controller
  * Added pod anti-affinity rules to the control plane pods when HA is enabled
    (thanks @Pothulapati!)
* Proxy
  * Improved performance by using a constant-time load balancer
  * Added a new `/proxy-log-level` endpoint to update the log level at runtime

## stable-2.4.0

This release adds traffic splitting functionality, support for the Kubernetes
Service Mesh Interface (SMI), graduates high-availability support out of
experimental status, and adds a tremendous list of other improvements,
performance enhancements, and bug fixes.

Linkerd's new traffic splitting feature allows users to dynamically control the
percentage of traffic destined for a service. This powerful feature can be used
to implement rollout strategies like canary releases and blue-green deploys.
Support for the [Service Mesh Interface](https://smi-spec.io) (SMI) makes it
easier for ecosystem tools to work across all service mesh implementations.

Along with the introduction of optional install stages via the `linkerd install
config` and `linkerd install control-plane` commands, the default behavior of
the `linkerd inject` command only adds annotations and defers injection to the
always-installed proxy injector component.

Finally, there have been many performance and usability improvements to the
proxy and UI, as well as production-ready features including:
* A new `linkerd edges` command that provides fine-grained observability into
  the TLS-based identity system
* A `--enable-debug-sidecar` flag for the `linkerd inject` command that improves
  debugging efforts

Linkerd recently passed a CNCF-sponsored security audit! Check out the in-depth
report [here](https://github.com/linkerd/linkerd2/blob/master/SECURITY_AUDIT.pdf).

To install this release, run: `curl https://run.linkerd.io/install | sh`

**Upgrade notes**: Use the `linkerd upgrade` command to upgrade the control
plane. This command ensures that all existing control plane's configuration and
mTLS secrets are retained. For more details, please see the [upgrade
instructions](https://linkerd.io/2/tasks/upgrade/#upgrade-notice-stable-2-4-0)
for more details.

**Special thanks to**: @alenkacz, @codeman9, @dwj300, @jackprice, @liquidslr,
@matej-g, @Pothulapati, @zaharidichev

**Full release notes**:

* CLI
  * **Breaking Change** Removed the `--proxy-auto-inject` flag, as the proxy
    injector is now always installed
  * **Breaking Change** Replaced the `--linkerd-version` flag with the
    `--proxy-version` flag in the `linkerd install` and `linkerd upgrade`
    commands, which allows setting the version for the injected proxy sidecar
    image, without changing the image versions for the control plane
  * Introduced install stages: `linkerd install config` and `linkerd install
    control-plane`
  * Introduced upgrade stages: `linkerd upgrade config` and `linkerd upgrade
    control-plane`
  * Introduced a new `--from-manifests` flag to `linkerd upgrade` allowing
    manually feeding a previously saved output of `linkerd install` into the
    command, instead of requiring a connection to the cluster to fetch the
    config
  * Introduced a new `--manual` flag to `linkerd inject` to output the proxy
    sidecar container spec
  * Introduced a new `--enable-debug-sidecar` flag to `linkerd inject`, that
    injects a debug sidecar to inspect traffic to and from the meshed pod
  * Added a new check for unschedulable pods and PSP issues (thanks,
    @liquidslr!)
  * Disabled the spinner in `linkerd check` when running without a TTY
  * Ensured the ServiceAccount for the proxy injector is created before its
    Deployment to avoid warnings when installing the proxy injector (thanks,
    @dwj300!)
  * Added a `linkerd check config` command for verifying that `linkerd install
    config` was successful
  * Improved the help documentation of `linkerd install` to clarify flag usage
  * Added support for private Kubernetes clusters by changing the CLI to connect
    to the control plane using a port-forward (thanks, @jackprice!)
  * Fixed `linkerd check` and `linkerd dashboard` failing when any control plane
    pod is not ready, even when multiple replicas exist (as in HA mode)
  * **New** Added a `linkerd edges` command that shows the source and
    destination name and identity for proxied connections, to assist in
    debugging
  * Tap can now be disabled for specific pods during injection by using the
    `--disable-tap` flag, or by using the `config.linkerd.io/disable-tap`
    annotation
  * Introduced pre-install healthcheck for clock skew (thanks, @matej-g!)
  * Added a JSON option to the `linkerd edges` command so that output is
    scripting friendly and can be parsed easily (thanks @alenkacz!)
  * Fixed an issue when Linkerd is installed with `--ha`, running `linkerd
    upgrade` without `--ha` will disable the high availability control plane
  * Fixed an issue with `linkerd upgrade` where running without `--ha` would
    unintentionally disable high availability features if they were previously
    enabled
  * Added a `--init-image-version` flag to `linkerd inject` to override the
    injected proxy-init container version
  * Added the `--linkerd-cni-enabled` flag to the `install` subcommands so that
    `NET_ADMIN` capability is omitted from the CNI-enabled control plane's PSP
  * Updated `linkerd check` to validate the caller can create
    `PodSecurityPolicy` resources
  * Added a check to `linkerd install` to prevent installing multiple control
    planes into different namespaces avoid conflicts between global resources
  * Added support for passing a URL directly to `linkerd inject` (thanks
    @Pothulapati!)
  * Added more descriptive output to the `linkerd check` output for control
    plane ReplicaSet readiness
  * Refactored the `linkerd endpoints` to use the same interface as used by the
    proxy for service discovery information
  * Fixed a bug where `linkerd inject` would fail when given a path to a file
    outside the current directory
  * Graduated high-availability support out of experimental status
  * Modified the error message for `linkerd install` to provide instructions for
    proceeding when an existing installation is found
* Controller
  * Added Go pprof HTTP endpoints to all control plane components' admin servers
    to better assist debugging efforts
  * Fixed bug in the proxy injector, where sporadically the pod workload owner
    wasn't properly determined, which would result in erroneous stats
  * Added support for a new `config.linkerd.io/disable-identity` annotation to
    opt out of identity for a specific pod
  * Fixed pod creation failure when a `ResourceQuota` exists by adding a default
    resource spec for the proxy-init init container
  * Fixed control plane components failing on startup when the Kubernetes API
    returns an `ErrGroupDiscoveryFailed`
  * Added Controller Component Labels to the webhook config resources (thanks,
    @Pothulapati!)
  * Moved the tap service into its own pod
  * **New** Control plane installations now generate a self-signed certificate
    and private key pair for each webhook, to prepare for future work to make
    the proxy injector and service profile validator HA
  * Added the ` config.linkerd.io/enable-debug-sidecar` annotation allowing the
    `--enable-debug-sidecar` flag to work when auto-injecting Linkerd proxies
  * Added multiple replicas for the `proxy-injector` and `sp-validator`
    controllers when run in high availability mode (thanks to @Pothulapati!)
  * Defined least privilege default security context values for the proxy
    container so that auto-injection does not fail (thanks @codeman9!)
  * Default the webhook failure policy to `Fail` in order to account for
    unexpected errors during auto-inject; this ensures uninjected applications
    are not deployed
  * Introduced control plane's PSP and RBAC resources into Helm templates; these
    policies are only in effect if the PSP admission controller is enabled
  * Removed `UPDATE` operation from proxy-injector webhook because pod mutations
    are disallowed during update operations
  * Default the mutating and validating webhook configurations `sideEffects`
    property to `None` to indicate that the webhooks have no side effects on
    other resources (thanks @Pothulapati!)
  * Added support for the SMI TrafficSplit API which allows users to define
    traffic splits in TrafficSplit custom resources
  * Added the `linkerd.io/control-plane-ns` label to all Linkerd resources
    allowing them to be identified using a label selector
  * Added Prometheus metrics for the Kubernetes watchers in the destination
    service for better visibility
* Proxy
  * Replaced the fixed reconnect backoff with an exponential one (thanks,
    @zaharidichev!)
  * Fixed an issue where load balancers can become stuck
  * Added a dispatch timeout that limits the amount of time a request can be
    buffered in the proxy
  * Removed the limit on the number of concurrently active service discovery
    queries to the destination service
  * Fix an epoll notification issue that could cause excessive CPU usage
  * Added the ability to disable tap by setting an env var (thanks,
    @zaharidichev!)
  * Changed the proxy's routing behavior so that, when the control plane does
    not resolve a destination, the proxy forwards the request with minimal
    additional routing logic
  * Fixed a bug in the proxy's HPACK codec that could cause requests with very
    large header values to hang indefinitely
  * Fixed a memory leak that can occur if an HTTP/2 request with a payload ends
    before the entire payload is sent to the destination
  * The `l5d-override-dst` header is now used for inbound service profile
    discovery
  * Added errors totals to `response_total` metrics
  * Changed the load balancer to require that Kubernetes services are resolved
    via the control plane
  * Added the `NET_RAW` capability to the proxy-init container to be compatible
    with `PodSecurityPolicy`s that use `drop: all`
  * Fixed the proxy rejecting HTTP2 requests that don't have an `:authority`
  * Improved idle service eviction to reduce resource consumption for clients
    that send requests to many services
  * Fixed proxied HTTP/2 connections returning 502 errors when the upstream
    connection is reset, rather than propagating the reset to the client
  * Changed the proxy to treat unexpected HTTP/2 frames as stream errors rather
    than connection errors
  * Fixed a bug where DNS queries could persist longer than necessary
  * Improved router eviction to remove idle services in a more timely manner
  * Fixed a bug where the proxy would fail to process requests with obscure
    characters in the URI
* Web UI
  * Added the Font Awesome stylesheet locally; this allows both Font Awesome and
    Material-UI sidebar icons to display consistently with no/limited internet
    access (thanks again, @liquidslr!)
  * Removed the Authorities table and sidebar link from the dashboard to prepare
    for a new, improved dashboard view communicating authority data
  * Fixed dashboard behavior that caused incorrect table sorting
  * Removed the "Debug" page from the Linkerd dashboard while the functionality
    of that page is being redesigned
  * Added an Edges table to the resource detail view that shows the source,
    destination name, and identity for proxied connections
  * Improved UI for Edges table in dashboard by changing column names, adding a
    "Secured" icon and showing an empty Edges table in the case of no returned
    edges
* Internal
  * Known container errors were hidden in the integration tests; now they are
    reported in the output without having the tests fail
  * Fixed integration tests by adding known proxy-injector log warning to tests
  * Modified the integration test for `linkerd upgrade` in order to test
    upgrading from the latest stable release instead of the latest edge and
    reflect the typical use case
  * Moved the proxy-init container to a separate `linkerd/proxy-init` Git
    repository

## edge-19.7.3

* CLI
  * Graduated high-availability support out of experimental status
  * Modified the error message for `linkerd install` to provide instructions for
    proceeding when an existing installation is found
* Controller
  * Added Prometheus metrics for the Kubernetes watchers in the destination
    service for better visibility

## edge-19.7.2

* CLI
  * Refactored the `linkerd endpoints` to use the same interface as used by the
    proxy for service discovery information
  * Fixed a bug where `linkerd inject` would fail when given a path to a file
    outside the current directory
* Proxy
  * Fixed a bug where DNS queries could persist longer than necessary
  * Improved router eviction to remove idle services in a more timely manner
  * Fixed a bug where the proxy would fail to process requests with obscure
    characters in the URI

## edge-19.7.1

* CLI
  * Added more descriptive output to the `linkerd check` output for control
    plane ReplicaSet readiness
  * **Breaking change** Renamed `config.linkerd.io/debug` annotation to
    `config.linkerd.io/enable-debug-sidecar`, to match the
    `--enable-debug-sidecar` CLI flag that sets it
  * Fixed a bug in `linkerd edges` that caused incorrect identities to be
    displayed when requests were sent from two or more namespaces
* Controller
  * Added the `linkerd.io/control-plane-ns` label to the SMI Traffic Split CRD
* Proxy
  * Fixed proxied HTTP/2 connections returning 502 errors when the upstream
    connection is reset, rather than propagating the reset to the client
  * Changed the proxy to treat unexpected HTTP/2 frames as stream errors rather
    than connection errors

## edge-19.6.4

This release adds support for the SMI [Traffic Split](https://github.com/deislabs/smi-spec/blob/master/traffic-split.md)
API. Creating a TrafficSplit resource will cause Linkerd to split traffic
between the specified backend services. Please see [the spec](https://github.com/deislabs/smi-spec/blob/master/traffic-split.md)
for more details.

* CLI
  * Added a check to `install` to prevent installing multiple control planes
    into different namespaces
  * Added support for passing a URL directly to `linkerd inject` (thanks
    @Pothulapati!)
  * Added the `--all-namespaces` flag to `linkerd edges`
* Controller
  * Added support for the SMI TrafficSplit API which allows users to define
    traffic splits in TrafficSplit custom resources
* Web UI
  * Improved UI for Edges table in dashboard by changing column names, adding a
    "Secured" icon and showing an empty Edges table in the case of no returned
    edges

## edge-19.6.3

* CLI
  * Updated `linkerd check` to validate the caller can create
    `PodSecurityPolicy` resources
* Controller
  * Default the mutating and validating webhook configurations `sideEffects`
    property to `None` to indicate that the webhooks have no side effects on
    other resources (thanks @Pothulapati!)
* Proxy
  * Added the `NET_RAW` capability to the proxy-init container to be compatible
    with `PodSecurityPolicy`s that use `drop: all`
  * Fixed the proxy rejecting HTTP2 requests that don't have an `:authority`
  * Improved idle service eviction to reduce resource consumption for clients
    that send requests to many services
* Web UI
  * Removed the "Debug" page from the Linkerd dashboard while the functionality
    of that page is being redesigned
  * Added an Edges table to the resource detail view that shows the source,
    destination name, and identity for proxied connections

## edge-19.6.2

* CLI
  * Added the `--linkerd-cni-enabled` flag to the `install` subcommands so that
    `NET_ADMIN` capability is omitted from the CNI-enabled control plane's PSP
* Controller
  * Default to least-privilege security context values for the proxy container
    so that auto-inject does not fail on restricted PSPs (thanks @codeman9!)
  * Defined least privilege default security context values for the proxy
    container so that auto-injection does not fail on (thanks @codeman9!)
  * Default the webhook failure policy to `Fail` in order to account for
    unexpected errors during auto-inject; this ensures uninjected applications
    are not deployed
  * Introduced control plane's PSP and RBAC resources into Helm templates;
    these policies are only in effect if the PSP admission controller is
    enabled
  * Removed `UPDATE` operation from proxy-injector webhook because pod
    mutations are disallowed during update operations
* Proxy
  * The `l5d-override-dst` header is now used for inbound service profile
    discovery
  * Include errors in `response_total` metrics
  * Changed the load balancer to require that Kubernetes services are resolved
    via the control plane
* Web UI
  * Fixed dashboard behavior that caused incorrect table sorting

## edge-19.5.4

* CLI
  * Fixed an issue where, when Linkerd is installed with `--ha`, running
    `linkerd upgrade` without `--ha` will disable the high availability
    control plane
  * Added a `--init-image-version` flag to `linkerd inject` to override the
    injected proxy-init container version
* Controller
  * Added multiple replicas for the `proxy-injector` and `sp-validator`
    controllers when run in high availability mode (thanks to @Pothulapati!)
* Proxy
  * Fixed a memory leak that can occur if an HTTP/2 request with a payload
    ends before the entire payload is sent to the destination
* Internal
  * Moved the proxy-init container to a separate `linkerd/proxy-init` Git
    repository

## stable-2.3.2

This stable release fixes a memory leak in the proxy.

To install this release, run: `curl https://run.linkerd.io/install | sh`

**Full release notes**:

* Proxy
  * Fixed a memory leak that can occur if an HTTP/2 request with a payload
    ends before the entire payload is sent to the destination

## edge-19.5.4

* CLI
  * Added a JSON option to the `linkerd edges` command so that output is
    scripting friendly and can be parsed easily (thanks @alenkacz!)
* Controller
  * **New** Control plane installations now generate a self-signed certificate
    and private key pair for each webhook, to prepare for future work to make
    the proxy injector and service profile validator HA
  * Added a debug container annotation, allowing the `--enable-debug-sidecar`
    flag to work when auto-injecting Linkerd proxies
* Proxy
  * Changed the proxy's routing behavior so that, when the control plane does
    not resolve a destination, the proxy forwards the request with minimal
    additional routing logic
  * Fixed a bug in the proxy's HPACK codec that could cause requests with very
    large header values to hang indefinitely
* Web UI
  * Removed the Authorities table and sidebar link from the dashboard to prepare
    for a new, improved dashboard view communicating authority data
* Internal
  * Modified the integration test for `linkerd upgrade` to test upgrading from
    the latest stable release instead of the latest edge, to reflect the typical
    use case

## stable-2.3.1

This stable release adds a number of proxy stability improvements.

To install this release, run: `curl https://run.linkerd.io/install | sh`

**Special thanks to**: @zaharidichev and @11Takanori!

**Full release notes**:

* Proxy
  * Changed the proxy's routing behavior so that, when the control plane
    does not resolve a destination, the proxy forwards the request with minimal
    additional routing logic
  * Fixed a bug in the proxy's HPACK codec that could cause requests with
    very large header values to hang indefinitely
  * Replaced the fixed reconnect backoff with an exponential one (thanks,
    @zaharidichev!)
  * Fixed an issue where requests could be held indefinitely by the load balancer
  * Added a dispatch timeout that limits the amount of time a request can be
    buffered in the proxy
  * Removed the limit on the number of concurrently active service discovery
    queries to the destination service
  * Fixed an epoll notification issue that could cause excessive CPU usage
  * Added the ability to disable tap by setting an env var (thanks,
    @zaharidichev!)

## edge-19.5.3

* CLI
  * **New** Added a `linkerd edges` command that shows the source and
    destination name and identity for proxied connections, to assist in
    debugging
  * Tap can now be disabled for specific pods during injection by using the
    `--disable-tap` flag, or by using the `config.linkerd.io/disable-tap`
    annotation
  * Introduced pre-install healthcheck for clock skew (thanks, @matej-g!)
* Controller
  * Added Controller Component Labels to the webhook config resources (thanks,
    @Pothulapati!)
  * Moved the tap service into its own pod
* Proxy
  * Fix an epoll notification issue that could cause excessive CPU usage
  * Added the ability to disable tap by setting an env var (thanks,
    @zaharidichev!)

## edge-19.5.2

* CLI
  * Fixed `linkerd check` and `linkerd dashboard` failing when any control plane
    pod is not ready, even when multiple replicas exist (as in HA mode)
* Controller
  * Fixed control plane components failing on startup when the Kubernetes API
    returns an `ErrGroupDiscoveryFailed`
* Proxy
  * Added a dispatch timeout that limits the amount of time a request can be
    buffered in the proxy
  * Removed the limit on the number of concurrently active service discovery
    queries to the destination service

Special thanks to @zaharidichev for adding end to end tests for proxies with
TLS!

## edge-19.5.1

* CLI
  * Added a `linkerd check config` command for verifying that
    `linkerd install config` was successful
  * Improved the help documentation of `linkerd install` to clarify flag usage
  * Added support for private Kubernetes clusters by changing the CLI to connect
    to the control plane using a port-forward (thanks, @jackprice!)
* Controller
  * Fixed pod creation failure when a `ResourceQuota` exists by adding a default
    resource spec for the proxy-init init container
* Proxy
  * Replaced the fixed reconnect backoff with an exponential one (thanks,
    @zaharidichev!)
  * Fixed an issue where load balancers can become stuck
* Internal
  * Fixed integration tests by adding known proxy-injector log warning to tests

## edge-19.4.5

**Significant Update**

As of this edge release the proxy injector component is always installed.
To have the proxy injector inject a pod you still can manually add the
`linkerd.io/inject: enable` annotation into the pod spec, or at the namespace
level to have all your pods be injected by default.
With this release the behaviour of the `linkerd inject` command changes, where
the proxy sidecar container YAML is no longer included in its output by
default, but instead it will just add the annotations to defer the injection to
the proxy injector.
For use cases that require the full injected YAML to be output, a new
`--manual` flag has been added.

Another important update is the introduction of install stages. You still have
the old `linkerd install` command, but now it can be broken into
`linkerd install config` which installs the resources that require
cluster-level privileges, and `linkerd install control-plane` that continues
with the resources that only require namespace-level privileges.
This also applies to the `linkerd upgrade` command.

* CLI
  * **Breaking Change** Removed the `--proxy-auto-inject` flag, as the
    proxy injector is now always installed
  * **Breaking Change** Replaced the `--linkerd-version` flag with the
    `--proxy-version` flag in the `linkerd install` and `linkerd upgrade`
    commands, which allows setting the version for the injected proxy sidecar
    image, without changing the image versions for the control plane
  * Introduced install stages: `linkerd install config` and
    `linkerd install control-plane`
  * Introduced upgrade stages: `linkerd upgrade config` and
    `linkerd upgrade control-plane`
  * Introduced a new `--from-manifests` flag to `linkerd upgrade` allowing
    manually feeding a previously saved output of `linkerd install` into the
    command, instead of requiring a connection to the cluster to fetch the
    config
  * Introduced a new `--manual` flag to `linkerd inject` to output the proxy
    sidecar container spec
  * Introduced a new `--enable-debug-sidecar` option to `linkerd inject`, that
    injects a debug sidecar to inspect traffic to and from the meshed pod
  * Added a new check for unschedulable pods and PSP issues (thanks, @liquidslr!)
  * Disabled the spinner in `linkerd check` when running without a TTY
  * Ensured the ServiceAccount for the proxy injector is created before its
    Deployment to avoid warnings when installing the proxy injector
    (thanks, @dwj300!)

* Controller
  * Added Go pprof HTTP endpoints to all control plane components' admin
    servers to better assist debugging efforts
  * Fixed bug in the proxy injector, where sporadically the pod workload owner
    wasn't properly determined, which would result in erroneous stats
  * Added support for a new `config.linkerd.io/disable-identity` annotation to
    opt out of identity for a specific pod

* Web UI
  * Added the Font Awesome stylesheet locally; this allows both Font Awesome
    and Material-UI sidebar icons to display consistently with no/limited
    internet access (thanks again, @liquidslr!)

* Internal
  * Known container errors were hidden in the integration tests; now they are
    reported in the output, still without having the tests fail

## stable-2.3.0

This stable release introduces a new TLS-based service identity system into the
default Linkerd installation, replacing `--tls=optional` and the `linkerd-ca`
controller. Now, proxies generate ephemeral private keys into a tmpfs directory
and dynamically refresh certificates, authenticated by Kubernetes ServiceAccount
tokens, and tied to ServiceAccounts as the identity primitive

In this release, all meshed HTTP communication is private and authenticated by
default.

Among the many improvements to the web dashboard, we've added a Community page
to surface news and updates from linkerd.io.

For more details, see the announcement blog post:
https://linkerd.io/2019/04/16/announcing-linkerd-2.3/

To install this release, run: `curl https://run.linkerd.io/install | sh`

**Upgrade notes**: The `linkerd-ca` controller has been removed in favor of the
`linkerd-identity` controller. If you had previously installed Linkerd with
`--tls=optional`, manually delete the `linkerd-ca` deployment after upgrading.
Also, `--single-namespace` mode is no longer supported. For full details on
upgrading to this release, please see the
[upgrade instructions](https://linkerd.io/2/tasks/upgrade/#upgrade-notice-stable-2-3-0).

**Special thanks to**: @codeman9, @harsh-98, @huynq0911, @KatherineMelnyk,
@liquidslr, @paranoidaditya, @Pothulapati, @TwinProduction, and @yb172!

**Full release notes**:

* CLI
  * Introduced an `upgrade` command! This allows an existing Linkerd control
    plane to be reinstalled or reconfigured; it is particularly useful for
    automatically reusing flags set in the previous `install` or `upgrade`
  * Introduced the `linkerd metrics` command for fetching proxy metrics
  * **Breaking Change:** The `--linkerd-cni-enabled` flag has been removed from
    the `inject` command; CNI is configured at the cluster level with the
    `install` command and no longer applies to the `inject` command
  * **Breaking Change** Removed the `--disable-external-profiles` flag from the
    `install` command; external profiles are now disabled by default and can be
    enabled with the new `--enable-external-profiles` flag
  * **Breaking change** Removed the `--api-port` flag from the `inject` and
    `install` commands, since there's no benefit to running the control plane's
    destination API on a non-default port (thanks, @paranoidaditya)
  * **Breaking change** Removed the `--tls=optional` flag from the
    `linkerd install` command, since TLS is now enabled by default
  * Changed `install` to accept or generate an issuer Secret for the Identity
    controller
  * Changed `install` to fail in the case of a conflict with an existing
    installation; this can be disabled with the `--ignore-cluster` flag
  * Added the ability to adjust the Prometheus log level via
    `--controller-log-level`
  * Implemented `--proxy-cpu-limit` and `--proxy-memory-limit` for setting the
    proxy resources limits (`--proxy-cpu` and `--proxy-memory` were deprecated in
    favor of `proxy-cpu-request` and `proxy-memory-request`) (thanks @TwinProduction!)
  * Added a validator for the `--proxy-log-level` flag
  * Updated the `inject` and `uninject` subcommands to issue warnings when
    resources lack a `Kind` property (thanks @Pothulapati!)
  * The `inject` command proxy options are now converted into config
    annotations; the annotations ensure that these configs are persisted in
    subsequent resource updates
  * Changed `inject` to require fetching a configuration from the control plane;
    this can be disabled with the `--ignore-cluster` and `--disable-identity`
    flags, though this will prevent the injected pods from participating in mesh
    identity
  * Included kubectl version check as part of `linkerd check` (thanks @yb172!)
  * Updated `linkerd check` to ensure hint URLs are displayed for RPC checks
  * Fixed sporadic (and harmless) race condition error in `linkerd check`
  * Introduced a check for NET_ADMIN in `linkerd check`
  * Fixed permissions check for CRDs
  * Updated the `linkerd dashboard` command to serve the dashboard on a fixed
    port, allowing it to leverage browser local storage for user settings
  * Updated the `linkerd routes` command to display rows for routes that are not
    receiving any traffic
  * Added TCP stats to the stat command, under the `-o wide` and `-o json` flags
  * The `stat` command now always shows the number of open TCP connections
  * Removed TLS metrics from the `stat` command; this is in preparation for
    surfacing identity metrics in a clearer way
  * Exposed the `install-cni` command and its flags, and tweaked their descriptions
  * Eliminated false-positive vulnerability warnings related to go.uuid
* Controller
  * Added a new public API endpoint for fetching control plane configuration
  * **Breaking change** Removed support for running the control plane in
    single-namespace mode, which was severely limited in the number of features
    it supported due to not having access to cluster-wide resources; the end
    goal being Linkerd degrading gracefully depending on its privileges
  * Updated automatic proxy injection and CLI injection to support overriding
    inject defaults via pod spec annotations
  * Added support for the `config.linkerd.io/proxy-version` annotation on pod
    specs; this will override the injected proxy version
  * The auto-inject admission controller webhook is updated to watch pods
    creation and update events; with this change, proxy auto-injection now works
    for all kinds of workloads, including StatefulSets, DaemonSets, Jobs, etc
  * Service profile validation is now performed via a webhook endpoint; this
    prevents Kubernetes from accepting invalid service profiles
  * Changed the default CPU request from `10m` to `100m` for HA deployments;
    this will help some intermittent liveness/readiness probes from failing due
    to tight resource constraints
  * Updated destination service to return TLS identities only when the
    destination pod is TLS-aware and is in the same controller namespace
  * Lessen klog level to improve security
  * Updated control plane components to query Kubernetes at startup to determine
    authorized namespaces and if ServiceProfile support is available
  * Modified the stats payload to include the following TCP stats:
    `tcp_open_connections`, `tcp_read_bytes_total`, `tcp_write_bytes_total`
  * Instrumented clients in the control plane connecting to Kubernetes, thus
    providing better visibility for diagnosing potential problems with those
    connections
  * Renamed the "linkerd-proxy-api" service to "linkerd-destination"
  * Bumped Prometheus to version 2.7.1 and Grafana to version 5.4.3
* Proxy
  * Introduced per-proxy private key generation and dynamic certificate renewal
  * **Fixed** a connection starvation issue where TLS discovery detection on
    slow or idle connections could block all other connections from being
    accepted on the inbound listener of the proxy
  * **Fixed** a stream leak between the proxy and the control plane that could
    cause the `linkerd-controller` pod to use an excessive amount of memory
  * Added a readiness check endpoint on `:4191/ready` so that Kubernetes doesn't
    consider pods ready until they have acquired a certificate from the Identity
    controller
  * Some `l5d-*` informational headers have been temporarily removed from
    requests and responses because they could leak information to external
    clients
  * The proxy's connect timeouts have been updated, especially to improve
    reconnect behavior between the proxy and the control plane
  * Increased the inbound/router cap on MAX_CONCURRENT_STREAMS
  * The `l5d-remote-ip` header is now set on inbound requests and outbound
    responses
  * Fixed issue with proxy falling back to filesystem polling due to improperly
    sized inotify buffer
* Web UI
  * **New** Added a Community page to surface news and updates from linkerd.io
  * Added a Debug page to the web dashboard, allowing you to introspect service
    discovery state
  * The Overview page in the Linkerd dashboard now renders appropriately when
    viewed on mobile devices
  * Added filter functionality to the metrics tables
  * Added stable sorting for table rows
  * Added TCP stats to the Linkerd Pod Grafana dashboard
  * Added TCP stat tables on the namespace landing page and resource detail page
  * The topology graph now shows TCP stats if no HTTP stats are available
  * Improved table display on the resource detail page for resources with
    TCP-only traffic
  * Updated the resource detail page to start displaying a table with TCP stats
  * Modified the Grafana variable queries to use a TCP-based metric, so that
    if there is only TCP traffic then the dropdowns don't end up empty
  * Fixed sidebar not updating when resources were added/deleted (thanks
    @liquidslr!)
  * Added validation to the "new service profile" form (thanks @liquidslr!)
  * Added a Grafana dashboard and web tables for displaying Job stats
    (thanks, @Pothulapati!)
  * Removed TLS columns from the dashboard tables; this is in preparation for
    surfacing identity metrics in a clearer way
  * Fixed the behavior of the Top query 'Start' button if a user's query returns
    no data
  * Fixed an issue with the order of tables returned from a Top Routes query
  * Added text wrap for paths in the modal for expanded Tap query data
  * Fixed a quoting issue with service profile downloads (thanks, @liquidslr!)
  * Updated sorting of route table to move default routes to the bottom
  * Removed 'Help' hierarchy and surfaced links on navigation sidebar
  * Ensured that all the tooltips in Grafana displaying the series are shared
    across all the graphs
* Internals
  * Improved the `bin/go-run` script for the build process so that on failure,
    all associated background processes are terminated
  * Added more log errors to the integration tests
  * Removed the GOPATH dependence from the CLI dev environment
  * Consolidated injection code from CLI and admission controller code paths
  * Enabled the following linters: `unparam`, `unconvert`, `goimports`,
    `goconst`, `scopelint`, `unused`, `gosimple`
  * Bumped base Docker images
  * Added the flags `-update` and `-pretty-diff` to tests to allow overwriting
    fixtures and to print the full text of the fixtures upon mismatches
  * Introduced golangci-lint tooling, using `.golangci.yml` to centralize
    the config
  * Added a `-cover` parameter to track code coverage in go tests
    (more info in TEST.md)
  * Renamed a function in a test that was shadowing a go built-in function
    (thanks @huynq0911!)

## edge-19.4.4

* Proxy
  * **Fixed** a connection starvation issue where TLS discovery detection on
    slow or idle connections could block all other connections from being
    accepted on the inbound listener of the proxy
* CLI
  * **Fixed** `inject` to allow the `--disable-identity` flag to be used
    without having to specify the `--ignore-cluster` flag
* Web UI
  * The Overview page in the Linkerd dashboard now renders appropriately when
    viewed on mobile devices

## edge-19.4.3

* CLI
  * **Fixed** `linkerd upgrade` command not upgrading proxy containers (thanks
    @jon-walton for the issue report!)
  * **Fixed** `linkerd upgrade` command not installing the identity service when
    it was not already installed
  * Eliminate false-positive vulnerability warnings related to go.uuid

Special thanks to @KatherineMelnyk for updating the web component to read the
UUID from the `linkerd-config` ConfigMap!

## edge-19.4.2

* CLI
  * Removed TLS metrics from the `stat` command; this is in preparation for
    surfacing identity metrics in a clearer way
  * The `upgrade` command now outputs a URL that explains next steps for
    upgrading
  * **Breaking Change:** The `--linkerd-cni-enabled` flag has been removed from
    the `inject` command; CNI is configured at the cluster level with the
    `install` command and no longer applies to the `inject` command
* Controller
  * Service profile validation is now performed via a webhook endpoint; this
    prevents Kubernetes from accepting invalid service profiles
  * Added support for the `config.linkerd.io/proxy-version` annotation on pod
    specs; this will override the injected proxy version
  * Changed the default CPU request from `10m` to `100m` for HA deployments;
    this will help some intermittent liveness/readiness probes from failing due
    to tight resource constraints
* Proxy
  * The `CommonName` field on CSRs is now set to the proxy's identity name
* Web UI
  * Removed TLS columns from the dashboard tables; this is in preparation for
    surfacing identity metrics in a clearer way

## edge-19.4.1

* CLI
  * Introduced an `upgrade` command! This allows an existing Linkerd control
    plane to be reinstalled or reconfigured; it is particularly useful for
    automatically reusing flags set in the previous `install` or `upgrade`
  * The `inject` command proxy options are now converted into config
    annotations; the annotations ensure that these configs are persisted in
    subsequent resource updates
  * The `stat` command now always shows the number of open TCP connections
  * **Breaking Change** Removed the `--disable-external-profiles` flag from the
    `install` command; external profiles are now disabled by default and can be
    enabled with the new `--enable-external-profiles` flag
* Controller
  * The auto-inject admission controller webhook is updated to watch pods
    creation and update events; with this change, proxy auto-injection now works
    for all kinds of workloads, including StatefulSets, DaemonSets, Jobs, etc
* Proxy
  * Some `l5d-*` informational headers have been temporarily removed from
    requests and responses because they could leak information to external
    clients
* Web UI
  * The topology graph now shows TCP stats if no HTTP stats are available
  * Improved table display on the resource detail page for resources with
    TCP-only traffic
  * Added validation to the "new service profile" form (thanks @liquidslr!)

## edge-19.3.3

**Significant Update**

This edge release introduces a new TLS Identity system into the default Linkerd
installation, replacing `--tls=optional` and the `linkerd-ca` controller. Now,
proxies generate ephemeral private keys into a tmpfs directory and dynamically
refresh certificates, authenticated by Kubernetes ServiceAccount tokens, via the
newly-introduced Identity controller.

Now, all meshed HTTP communication is private and authenticated by default.

* CLI
  * Changed `install` to accept or generate an issuer Secret for the Identity
    controller
  * Changed `install` to fail in the case of a conflict with an existing
    installation; this can be disabled with the `--ignore-cluster` flag
  * Changed `inject` to require fetching a configuration from the control plane;
    this can be disabled with the `--ignore-cluster` and `--disable-identity`
    flags, though this will prevent the injected pods from participating in mesh
    identity
  * **Breaking change** Removed the `--tls=optional` flag from the
    `linkerd install` command, since TLS is now enabled by default
  * Added the ability to adjust the Prometheus log level
* Proxy
  * **Fixed** a stream leak between the proxy and the control plane that could
    cause the `linkerd-controller` pod to use an excessive amount of memory
  * Introduced per-proxy private key generation and dynamic certificate renewal
  * Added a readiness check endpoint on `:4191/ready` so that Kubernetes doesn't
    consider pods ready until they have acquired a certificate from the Identity
    controller
  * The proxy's connect timeouts have been updated, especially to improve
    reconnect behavior between the proxy and the control plane
* Web UI
  * Added TCP stats to the Linkerd Pod Grafana dashboard
  * Fixed the behavior of the Top query 'Start' button if a user's query returns
    no data
  * Added stable sorting for table rows
  * Fixed an issue with the order of tables returned from a Top Routes query
  * Added text wrap for paths in the modal for expanded Tap query data
* Internal
  * Improved the `bin/go-run` script for the build process so that on failure,
    all associated background processes are terminated

Special thanks to @liquidslr for many useful UI and log changes, and to @mmalone
and @sourishkrout at @smallstep for collaboration and advice on the Identity
system!

## edge-19.3.2

* Controller
  * **Breaking change** Removed support for running the control plane in
    single-namespace mode, which was severely limited in the number of features
    it supported due to not having access to cluster-wide resources
  * Updated automatic proxy injection and CLI injection to support overriding
    inject defaults via pod spec annotations
  * Added a new public API endpoint for fetching control plane configuration
* CLI
  * **Breaking change** Removed the `--api-port` flag from the `inject` and
    `install` commands, since there's no benefit to running the control plane's
    destination API on a non-default port (thanks, @paranoidaditya)
  * Introduced the `linkerd metrics` command for fetching proxy metrics
  * Updated the `linkerd routes` command to display rows for routes that are not
    receiving any traffic
  * Updated the `linkerd dashboard` command to serve the dashboard on a fixed
    port, allowing it to leverage browser local storage for user settings
* Web UI
  * **New** Added a Community page to surface news and updates from linkerd.io
  * Fixed a quoting issue with service profile downloads (thanks, @liquidslr!)
  * Added a Grafana dashboard and web tables for displaying Job stats
    (thanks, @Pothulapati!)
  * Updated sorting of route table to move default routes to the bottom
  * Added TCP stat tables on the namespace landing page and resource detail page

## edge-19.3.1

* CLI
  * Introduced a check for NET_ADMIN in `linkerd check`
  * Fixed permissions check for CRDs
  * Included kubectl version check as part of `linkerd check` (thanks @yb172!)
  * Added TCP stats to the stat command, under the `-o wide` and `-o json` flags
* Controller
  * Updated the `mutatingwebhookconfiguration` so that it is recreated when the
    proxy injector is restarted, so that the MWC always picks up the latest
    config template during version upgrade
* Proxy
  * Increased the inbound/router cap on MAX_CONCURRENT_STREAMS
  * The `l5d-remote-ip` header is now set on inbound requests and outbound
    responses
* Web UI
  * Fixed sidebar not updating when resources were added/deleted (thanks
    @liquidslr!)
  * Added filter functionality to the metrics tables
* Internal
  * Added more log errors to the integration tests
  * Removed the GOPATH dependence from the CLI dev environment
  * Consolidated injection code from CLI and admission controller code paths

## edge-19.2.5

* CLI
  * Updated `linkerd check` to ensure hint URLs are displayed for RPC checks
* Controller
  * Updated the auto-inject admission controller webhook to respond to UPDATE
    events for deployment workloads
  * Updated destination service to return TLS identities only when the
    destination pod is TLS-aware and is in the same controller namespace
  * Lessen klog level to improve security
  * Updated control plane components to query Kubernetes at startup to determine
    authorized namespaces and if ServiceProfile support is available
  * Modified the stats payload to include the following TCP stats:
    `tcp_open_connections`, `tcp_read_bytes_total`, `tcp_write_bytes_total`
* Proxy
  * Fixed issue with proxy falling back to filesystem polling due to improperly
    sized inotify buffer
* Web UI
  * Removed 'Help' hierarchy and surfaced links on navigation sidebar
  * Added a Debug page to the web dashboard, allowing you to introspect service
    discovery state
  * Updated the resource detail page to start displaying a table with TCP stats
* Internal
  * Enabled the following linters: `unparam`, `unconvert`, `goimports`,
    `goconst`, `scopelint`, `unused`, `gosimple`
  * Bumped base Docker images

## stable-2.2.1

This stable release polishes some of the CLI help text and fixes two issues that
came up since the stable-2.2.0 release.

To install this release, run: `curl https://run.linkerd.io/install | sh`

**Full release notes**:

* CLI
  * Fixed handling of kubeconfig server urls that include paths
  * Updated the description of the `--proxy-auto-inject` flag to indicate that
    it is no longer experimental
  * Updated the `profile` help text to match the other commands
  * Added the "ep" alias for the `endpoints` command
* Controller
  * Stopped logging an error when a route doesn't specify a timeout

## edge-19-2.4

* CLI
  * Implemented `--proxy-cpu-limit` and `--proxy-memory-limit` for setting the
    proxy resources limits (`--proxy-cpu` and `--proxy-memory` were deprecated
    in favor of `proxy-cpu-request` and `proxy-memory-request`) (thanks
    @TwinProduction!)
  * Updated the `inject` and `uninject` subcommands to issue warnings when
    resources lack a `Kind` property (thanks @Pothulapati!)
  * Exposed the `install-cni` command and its flags, and tweaked their
    descriptions
  * Fixed handling of kubeconfig server urls that include paths
  * Updated the description of the `--proxy-auto-inject` flag to indicate that
    it is no longer experimental
  * Updated the `profile` help text to match the other commands
  * Added the "ep" alias for the `endpoints` command (also @Pothulapati!)
  * Added a validator for the `--proxy-log-level` flag
  * Fixed sporadic (and harmless) race condition error in `linkerd check`
* Controller
  * Instrumented clients in the control plane connecting to Kubernetes, thus
    providing better visibility for diagnosing potential problems with those
    connections
  * Stopped logging an error when a route doesn't specify a timeout
  * Renamed the "linkerd-proxy-api" service to "linkerd-destination"
  * Bumped Prometheus to version 2.7.1 and Grafana to version 5.4.3
* Web UI
  * Modified the Grafana variable queries to use a TCP-based metric, so that
    if there is only TCP traffic then the dropdowns don't end up empty
  * Ensured that all the tooltips in Grafana displaying the series are shared
    across all the graphs
* Internals
  * Added the flags `-update` and `-pretty-diff` to tests to allow overwriting
    fixtures and to print the full text of the fixtures upon mismatches
  * Introduced golangci-lint tooling, using `.golangci.yml` to centralize
    the config
  * Added a `-cover` parameter to track code coverage in go tests
    (more info in TEST.md)
  * Added integration tests for `--single-namespace`
  * Renamed a function in a test that was shadowing a go built-in function
    (thanks @huynq0911!)

## stable-2.2.0

This stable release introduces automatic request retries and timeouts, and
graduates auto-inject to be a fully-supported (non-experimental) feature. It
adds several new CLI commands, including `logs` and `endpoints`, that provide
diagnostic visibility into Linkerd's control plane. Finally, it introduces two
exciting experimental features: a cryptographically-secured client identity
header, and a CNI plugin that avoids the need for `NET_ADMIN` kernel
capabilities at deploy time.

For more details, see the announcement blog post:
https://blog.linkerd.io/2019/02/12/announcing-linkerd-2-2/

To install this release, run: `curl https://run.linkerd.io/install | sh`

**Upgrade notes**: The default behavior for proxy auto injection and service
profile ownership has changed as part of this release. Please see the
[upgrade instructions](https://linkerd.io/2/tasks/upgrade/#upgrade-notice-stable-2-2-0)
for more details.

**Special thanks to**: @alenkacz, @codeman9, @jonrichards, @radu-matei, @yeya24,
and @zknill

**Full release notes**:

* CLI
  * Improved service profile validation when running `linkerd check` in order to
    validate service profiles in all namespaces
  * Added the `linkerd endpoints` command to introspect Linkerd's service
    discovery state
  * Added the `--tap` flag to `linkerd profile` to generate service profiles
    using the route results seen during the tap
  * Added support for the `linkerd.io/inject: disabled` annotation on pod specs
    to disable injection for specific pods when running `linkerd inject`
  * Added support for `basePath` in OpenAPI 2.0 files when running `linkerd
    profile --open-api`
  * Increased `linkerd check` client timeout from 5 seconds to 30 seconds to fix
    issues for clusters with slow API servers
  * Updated `linkerd routes` to no longer return rows for `ExternalName`
    services in the namespace
  * Broadened the set of valid URLs when connecting to the Kubernetes API
  * Added the `--proto` flag to `linkerd profile` to output a service profile
    based on a Protobuf spec file
  * Fixed CLI connection failures to clusters that use self-signed certificates
  * Simplified `linkerd install` so that setting up proxy auto-injection
    (flag `--proxy-auto-inject`) no longer requires enabling TLS (flag `--tls`)
  * Added links for each `linkerd check` failure, pointing to a relevant section
    in our new FAQ page with resolution steps for each case
  * Added optional `linkerd install-sp` command to generate service profiles for
    the control plane, providing per-route metrics for control plane components
  * Removed `--proxy-bind-timeout` flag from `linkerd install` and
    `linkerd inject`, as the proxy no longer accepts this environment variable
  * Improved CLI appearance on Windows systems
  * Improved `linkerd check` output, fixed bug with `--single-namespace`
  * Fixed panic when `linkerd routes` is called in single-namespace mode
  * Added `linkerd logs` command to surface logs from any container in the
    Linkerd control plane
  * Added `linkerd uninject` command to remove the Linkerd proxy from a
    Kubernetes config
  * Improved `linkerd inject` to re-inject a resource that already has a Linkerd
    proxy
  * Improved `linkerd routes` to list all routes, including those without
    traffic
  * Improved readability in `linkerd check` and `linkerd inject` outputs
  * Adjusted the set of checks that are run before executing CLI commands, which
    allows the CLI to be invoked even when the control plane is not fully ready
  * Fixed reporting of injected resources when the `linkerd inject` command is
    run on `List` type resources with multiple items
  * Updated the `linkerd dashboard` command to use port-forwarding instead of
    proxying when connecting to the web UI and Grafana
  * Added validation for the `ServiceProfile` CRD
  * Updated the `linkerd check` command to disallow setting both the `--pre` and
    `--proxy` flags simultaneously
  * Added `--routes` flag to the `linkerd top` command, for grouping table rows
    by route instead of by path
  * Updated Prometheus configuration to automatically load `*_rules.yml` files
  * Removed TLS column from the `linkerd routes` command output
  * Updated `linkerd install` output to use non-default service accounts,
    `emptyDir` volume mounts, and non-root users
  * Removed cluster-wide resources from single-namespace installs
  * Fixed resource requests for proxy-injector container in `--ha` installs
* Controller
  * Fixed issue with auto-injector not setting the proxy ID, which is required
    to successfully locate client service profiles
  * Added full stat and tap support for DaemonSets and StatefulSets in the CLI,
    Grafana, and web UI
  * Updated auto-injector to use the proxy log level configured at install time
  * Fixed issue with auto-injector including TLS settings in injected pods even
    when TLS was not enabled
  * Changed automatic proxy injection to be opt-in via the `linkerd.io/inject`
    annotation on the pod or namespace
  * Move service profile definitions to client and server namespaces, rather
    than the control plane namespace
  * Added `linkerd.io/created-by` annotation to the linkerd-cni DaemonSet
  * Added a 10 second keepalive default to resolve dropped connections in Azure
    environments
  * Improved node selection for installing the linkerd-cni DaemonSet
  * Corrected the expected controller identity when configuring pods with TLS
  * Modified klog to be verbose when controller log-level is set to `debug`
  * Added support for retries and timeouts, configured directly in the service
    profile for each route
  * Added an experimental CNI plugin to avoid requiring the NET_ADMIN capability
    when injecting proxies
  * Improved the API for `ListPods`
  * Fixed `GetProfiles` API call not returning immediately when no profile
    exists (resulting in proxies logging warnings)
  * Blocked controller initialization until caches have synced with kube API
  * Fixed proxy-api handling of named target ports in service configs
  * Added parameter to stats API to skip retrieving prometheus stats
* Web UI
  * Updated navigation to link the Linkerd logo back to the Overview page
  * Fixed console warnings on the Top page
  * Grayed-out the tap icon for requests from sources that are not meshed
  * Improved resource detail pages to show all resource types
  * Fixed stats not appearing for routes that have service profiles installed
  * Added "meshed" and "no traffic" badges on the resource detail pages
  * Fixed `linkerd dashboard` to maintain proxy connection when browser open
    fails
  * Fixed JavaScript bundling to avoid serving old versions after upgrade
  * Reduced the size of the webpack JavaScript bundle by nearly 50%
  * Fixed an indexing error on the top results page
  * Restored unmeshed resources in the network graph on the resource detail page
  * Adjusted label for unknown routes in route tables, added tooltip
  * Updated Top Routes page to persist form settings in URL
  * Added button to create new service profiles on Top Routes page
  * Fixed CLI commands displayed when linkerd is running in non-default
    namespace
* Proxy
  * Modified the way in which canonicalization warnings are logged to reduce the
    overall volume of error logs and make it clearer when failures occur
  * Added TCP keepalive configuration to fix environments where peers may
    silently drop connections
  * Updated the `Get` and `GetProfiles` APIs to accept a `proxy_id` parameter in
    order to return more tailored results
  * Removed TLS fallback-to-plaintext if handshake fails
  * Added the ability to override a proxy's normal outbound routing by adding an
   `l5d-override-dst` header
  * Added `LINKERD2_PROXY_DNS_CANONICALIZE_TIMEOUT` environment variable to
    customize the timeout for DNS queries to canonicalize a name
  * Added support for route timeouts in service profiles
  * Improved logging for gRPC errors and for malformed HTTP/2 request headers
  * Improved log readability by moving some noisy log messages to more verbose
    log levels
  * Fixed a deadlock in HTTP/2 stream reference counts
  * Updated the proxy-init container to exit with a non-zero exit code if
    initialization fails, making initialization errors much more visible
  * Fixed a memory leak due to leaked UDP sockets for failed DNS queries
  * Improved configuration of the PeakEwma load balancer
  * Improved handling of ports configured to skip protocol detection when the
    proxy is running with TLS enabled

## edge-19.2.3

* Controller
  * Fixed issue with auto-injector not setting the proxy ID, which is required
    to successfully locate client service profiles
* Web UI
  * Updated navigation to link the Linkerd logo back to the Overview page
  * Fixed console warnings on the Top page

## edge-19.2.2

* CLI
  * Improved service profile validation when running `linkerd check` in order to
    validate service profiles in all namespaces
* Controller
  * Added stat and tap support for StatefulSets in the CLI, Grafana, and web UI
  * Updated auto-injector to use the proxy log level configured at install time
  * Fixed issue with auto-injector including TLS settings in injected pods even
    when TLS was not enabled
* Proxy
  * Modified the way in which canonicalization warnings are logged to reduce the
    overall volume of error logs and make it clearer when failures occur

## edge-19.2.1

* Controller
  * **Breaking change** Changed automatic proxy injection to be opt-in via the
    `linkerd.io/inject` annotation on the pod or namespace. More info:
    https://linkerd.io/2/proxy-injection/
  * **Breaking change** `ServiceProfile`s are now defined in client and server
    namespaces, rather than the control plane namespace. `ServiceProfile`s
    defined in the client namespace take priority over ones defined in the
    server namespace
  * Added `linkerd.io/created-by` annotation to the linkerd-cni DaemonSet
    (thanks @codeman9!)
  * Added a 10 second keepalive default to resolve dropped connections in Azure
    environments
  * Improved node selection for installing the linkerd-cni DaemonSet (thanks
    @codeman9!)
  * Corrected the expected controller identity when configuring pods with TLS
  * Modified klog to be verbose when controller log-level is set to `Debug`
* CLI
  * Added the `linkerd endpoints` command to introspect Linkerd's service
    discovery state
  * Added the `--tap` flag to `linkerd profile` to generate a `ServiceProfile`
    by using the route results seen during the tap
  * Added support for the `linkerd.io/inject: disabled` annotation on pod specs
    to disable injection for specific pods when running `linkerd inject`
  * Added support for `basePath` in OpenAPI 2.0 files when running `linkerd
    profile --open-api`
  * Increased `linkerd check` client timeout from 5 seconds to 30 seconds to fix
    issues for clusters with a slower API server
  * `linkerd routes` will no longer return rows for `ExternalName` services in
    the namespace
  * Broadened set of valid URLs when connecting to the Kubernetes API
  * Improved `ServiceProfile` field validation in `linkerd check`
* Proxy
  * Added TCP keepalive configuration to fix environments where peers may
    silently drop connections
  * The `Get` and `GetProfiles` API now accept a `proxy_id` parameter in order
    to return more tailored results
  * Removed TLS fallback-to-plaintext if handshake fails

## edge-19.1.4

* Controller
  * Added support for timeouts! Configurable in the service profiles for each
    route
  * Added an experimental CNI plugin to avoid requiring the NET_ADMIN capability
    when injecting proxies (more details at https://linkerd.io/2/cni) (thanks
    @codeman9!)
  * Added more improvements to the API for `ListPods` (thanks @alenkacz!)
* Web UI
  * Grayed-out the tap icon for requests from sources that are not meshed
* CLI
  * Added the `--proto` flag to `linkerd profile` to output a service profile
    based on a Protobuf spec file
  * Fixed CLI connection failure to clusters that use self-signed certificates
  * Simplified `linkerd install` so that setting up proxy auto-injection
    (flag `--proxy-auto-inject`) no longer requires enabling TLS (flag `--tls`)
  * Added links for each `linkerd check` failure, pointing to a relevant section
    in our new FAQ page with resolution steps for each case

## edge-19.1.3

* Controller
  * Improved API for `ListPods` (thanks @alenkacz!)
  * Fixed `GetProfiles` API call not returning immediately when no profile
    exists (resulting in proxies logging warnings)
* Web UI
  * Improved resource detail pages now show all resource types
  * Fixed stats not appearing for routes that have service profiles installed
* CLI
  * Added optional `linkerd install-sp` command to generate service profiles for
    the control plane, providing per-route metrics for control plane components
  * Removed `--proxy-bind-timeout` flag from `linkerd install` and
    `linkerd inject` commands, as the proxy no longer accepts this environment
    variable
  * Improved CLI appearance on Windows systems
  * Improved `linkerd check` output, fixed check bug when using
    `--single-namespace` (thanks to @djeeg for the bug report!)
  * Improved `linkerd stat` now supports DaemonSets (thanks @zknill!)
  * Fixed panic when `linkerd routes` is called in single-namespace mode
* Proxy
  * Added the ability to override a proxy's normal outbound routing by adding an
   `l5d-override-dst` header
  * Added `LINKERD2_PROXY_DNS_CANONICALIZE_TIMEOUT` environment variable to
    customize the timeout for DNS queries to canonicalize a name
  * Added support for route timeouts in service profiles
  * Improved logging for gRPC errors and for malformed HTTP/2 request headers
  * Improved log readability by moving some noisy log messages to more verbose
    log levels

## edge-19.1.2

* Controller
  * Retry support! Introduce an `isRetryable` property to service profiles to
    enable configuring retries on a per-route basis
* Web UI
  * Add "meshed" and "no traffic" badges on the resource detail pages
  * Fix `linkerd dashboard` to maintain proxy connection when browser open fails
  * Fix JavaScript bundling to avoid serving old versions after upgrade
* CLI
  * Add `linkerd logs` command to surface logs from any container in the Linkerd
    control plane (shout out to [Stern](https://github.com/wercker/stern)!)
  * Add `linkerd uninject` command to remove the Linkerd proxy from a Kubernetes
    config
  * Improve `linkerd inject` to re-inject a resource that already has a Linkerd
    proxy
  * Improve `linkerd routes` to list all routes, including those without traffic
  * Improve readability in `linkerd check` and `linkerd inject` outputs
* Proxy
  * Fix a deadlock in HTTP/2 stream reference counts

## edge-19.1.1

* CLI
  * Adjust the set of checks that are run before executing CLI commands, which
    allows the CLI to be invoked even when the control plane is not fully ready
  * Fix reporting of injected resources when the `linkerd inject` command is run
    on `List` type resources with multiple items
  * Update the `linkerd dashboard` command to use port-forwarding instead of
    proxying when connecting to the web UI and Grafana
  * Add validation for the `ServiceProfile` CRD (thanks, @alenkacz!)
  * Update the `linkerd check` command to disallow setting both the `--pre` and
    `--proxy` flags simultaneously (thanks again, @alenkacz!)
* Web UI
  * Reduce the size of the webpack JavaScript bundle by nearly 50%!
  * Fix an indexing error on the top results page
* Proxy
  * **Fixed** The proxy-init container now exits with a non-zero exit code if
    initialization fails, making initialization errors much more visible
  * **Fixed** The proxy previously leaked UDP sockets for failed DNS queries,
    causing a memory leak; this has been fixed

## edge-18.12.4

Upgrade notes: The control plane components have been renamed as of the
edge-18.12.1 release to reduce possible naming collisions. To upgrade an
older installation, see the [Upgrade Guide](https://linkerd.io/2/upgrade/).

* CLI
  * Add `--routes` flag to the `linkerd top` command, for grouping table rows
    by route instead of by path
  * Update Prometheus configuration to automatically load `*_rules.yml` files
  * Remove TLS column from the `linkerd routes` command output
* Web UI
  * Restore unmeshed resources in the network graph on the resource detail page
  * Reduce the overall size of the asset bundle for the web frontend
* Proxy
  * Improve configuration of the PeakEwma load balancer

Special thanks to @radu-matei for cleaning up a whole slew of Go lint warnings,
and to @jonrichards for improving the Rust build setup!

## edge-18.12.3

Upgrade notes: The control plane components have been renamed as of the
edge-18.12.1 release to reduce possible naming collisions. To upgrade an
older installation, see the [Upgrade Guide](https://linkerd.io/2/upgrade/).

* CLI
  * Multiple improvements to the `linkerd install` config (thanks @codeman9!)
    * Use non-default service accounts for grafana and web deployments
    * Use `emptyDir` volume mount for prometheus and grafana pods
    * Set security context on control plane components to not run as root
  * Remove cluster-wide resources from single-namespace installs
    * Disable service profiles in single-namespace mode
    * Require that namespace already exist for single-namespace installs
  * Fix resource requests for proxy-injector container in `--ha` installs
* Controller
  * Block controller initialization until caches have synced with kube API
  * Fix proxy-api handling of named target ports in service configs
  * Add parameter to stats API to skip retrieving prometheus stats (thanks,
    @alpeb!)
* Web UI
  * Adjust label for unknown routes in route tables, add tooltip
  * Update Top Routes page to persist form settings in URL
  * Add button to create new service profiles on Top Routes page
  * Fix CLI commands displayed when linkerd is running in non-default namespace
* Proxy
  * Proxies with TLS enabled now honor ports configured to skip protocol
    detection

## stable-2.1.0

This stable release introduces several major improvements, including per-route
metrics, service profiles, and a vastly improved dashboard UI. It also adds
several significant experimental features, including proxy auto-injection,
single namespace installs, and a high-availability mode for the control plane.

For more details, see the announcement blog post:
https://blog.linkerd.io/2018/12/06/announcing-linkerd-2-1/

To install this release, run: `curl https://run.linkerd.io/install | sh`

**Upgrade notes**: The control plane components have been renamed in this
release to reduce possible naming collisions. Please make sure to read the
[upgrade instructions](https://linkerd.io/2/upgrade/#upgrade-notice-stable-2-1-0)
if you are upgrading from the `stable-2.0.0` release.

**Special thanks to**: @alenkacz, @alpeb, @benjdlambert, @fahrradflucht,
@ffd2subroutine, @hypnoglow, @ihcsim, @lucab, and @rochacon

**Full release notes**:
* CLI
  * `linkerd routes` command displays per-route stats for *any resource*
  * Service profiles are now supported for external authorities
  * `linkerd routes --open-api` flag generates a service profile
    based on an OpenAPI specification (swagger) file
  * `linkerd routes` command displays per-route stats for services with
    service profiles
  * Add `--ha` flag to `linkerd install` command, for HA
    deployment of the control plane
  * Update stat command to accept multiple stat targets
  * Fix authority stat filtering when the `--from` flag is present
  * Various improvements to check command, including:
    * Emit warnings instead of errors when not running the latest version
    * Add retries if control plane health check fails initially
    * Run all pre-install RBAC checks, instead of stopping at first failure
  * Fixed an issue with the `--registry` install flag not accepting
    hosts with ports
  * Added an `--output` stat flag, for printing stats as JSON
  * Updated the `top` table to set column widths dynamically
  * Added a `--single-namespace` install flag for installing
    the control plane with Role permissions instead of ClusterRole permissions
  * Added a `--proxy-auto-inject` flag to the `install` command,
    allowing for auto-injection of sidecar containers
  * Added `--proxy-cpu` and `--proxy-memory` flags to the `install`
    and `inject` commands, giving the ability to configure CPU + Memory requests
  * Added a `--context` flag to specify the context to use to talk
    to the Kubernetes apiserver
  * The namespace in which Linkerd is installed is configurable via the
    `LINKERD_NAMESPACE` env var, in addition to the `--linkerd-namespace` flag
  * The wait time for the `check` and `dashboard` commands is
    configurable via the `--wait` flag
  * The `top` command now aggregates by HTTP method as well
* Controller
  * Rename snake case fields to camel case in service profile spec
  * Controller components are now prefixed with `linkerd-` to
    prevent name collisions with existing resources
  * `linkerd install --disable-h2-upgrade` flag has been added to
    control automatic HTTP/2 upgrading
  * Fix auto injection issue on Kubernetes `v1.9.11` that would
    merge, rather than append, the proxy container into the application
  * Fixed a few issues with auto injection via the proxy-injector webhook:
    * Injected pods now execute the linkerd-init container last, to avoid
      rerouting requests during pod init
    * Original pod labels and annotations are preserved when auto-injecting
  * CLI health check now uses unified endpoint for data plane checks
  * Include Licence files in all Docker images
* Proxy
  * The proxy's `tap` subsystem has been reimplemented to be more
    efficient and and reliable
    * The proxy now supports route metadata in tap queries and events
  * A potential HTTP/2 window starvation bug has been fixed
  * Prometheus counters now wrap properly for values greater than 2^53
  * Add controller client metrics, scoped under `control_`
  * Canonicalize outbound names via DNS for inbound profiles
  * Fix routing issue when a pod makes a request to itself
  * Only include `classification` label on `response_total` metric
  * Remove panic when failing to get remote address
  * Better logging in TCP connect error messages
* Web UI
  * Top routes page, served at `/routes`
  * Route metrics are now available in the resource detail pages for
    services with configured profiles
  * Service profiles can be created and downloaded from the Web UI
  * Top Routes page, served at `/routes`
  * Fixed a smattering of small UI issues
  * Added a new Grafana dashboard for authorities
  * Revamped look and feel of the Linkerd dashboard by switching
    component libraries from antd to material-ui
  * Added a Help section in the sidebar containing useful links
  * Tap and Top pages
    * Added clear button to query form
  * Resource Detail pages
    * Limit number of resources shown in the graph
  * Resource Detail page
    * Better rendering of the dependency graph at the top of the page
    * Unmeshed sources are now populated in the Inbound traffic table
    * Sources and destinations are aligned in the popover
  * Tap and Top pages
    * Additional validation and polish for the form controls
    * The top table clears older results when a new top call is started
    * The top table now aggregates by HTTP method as well

## edge-18.12.2

Upgrade notes: The control plane components have been renamed as of the
edge-18.12.1 release to reduce possible naming collisions. To upgrade an
older installation, see the [Upgrade Guide](https://linkerd.io/2/upgrade/).

* Controller
  * Rename snake case fields to camel case in service profile spec

## edge-18.12.1

Upgrade notes: The control plane components have been renamed in this release to
reduce possible naming collisions. To upgrade an existing installation:

* Install new CLI: `curl https://run.linkerd.io/install-edge | sh`
* Install new control plane: `linkerd install | kubectl apply -f -`
* Remove old deploys/cms:
  `kubectl -n linkerd get deploy,cm -oname | grep -v linkerd | xargs kubectl -n linkerd delete`
* Re-inject your applications: `linkerd inject my-app.yml | kubectl apply -f -`
* Remove old services:
  `kubectl -n linkerd get svc -oname | grep -v linkerd | xargs kubectl -n linkerd delete`

For more information, see the [Upgrade Guide](https://linkerd.io/2/upgrade/).

* CLI
  * **Improved** `linkerd routes` command displays per-route stats for
    *any resource*!
  * **New** Service profiles are now supported for external authorities!
  * **New** `linkerd routes --open-api` flag generates a service profile
    based on an OpenAPI specification (swagger) file
* Web UI
  * **New** Top routes page, served at `/routes`
  * **New** Route metrics are now available in the resource detail pages for
    services with configured profiles
  * **New** Service profiles can be created and downloaded from the Web UI
* Controller
  * **Improved** Controller components are now prefixed with `linkerd-` to
    prevent name collisions with existing resources
  * **New** `linkerd install --disable-h2-upgrade` flag has been added to
    control automatic HTTP/2 upgrading
* Proxy
  * **Improved** The proxy's `tap` subsystem has been reimplemented to be more
    efficient and and reliable
    * The proxy now supports route metadata in tap queries and events
  * **Fixed** A potential HTTP/2 window starvation bug has been fixed
  * **Fixed** Prometheus counters now wrap properly for values greater than
    2^53 (thanks, @lucab!)

## edge-18.11.3

* CLI
  * **New** `linkerd routes` command displays per-route stats for services with
    service profiles
  * **Experimental** Add `--ha` flag to `linkerd install` command, for HA
    deployment of the control plane (thanks @benjdlambert!)
* Web UI
  * **Experimental** Top Routes page, served at `/routes`
* Controller
  * **Fixed** Fix auto injection issue on Kubernetes `v1.9.11` that would
    merge, rather than append, the proxy container into the application
* Proxy
  * **Improved** Add controller client metrics, scoped under `control_`
  * **Improved** Canonicalize outbound names via DNS for inbound profiles

## edge-18.11.2

* CLI
  * **Improved** Update stat command to accept multiple stat targets
  * **Fixed** Fix authority stat filtering when the `--from` flag is present
  * Various improvements to check command, including:
    * Emit warnings instead of errors when not running the latest version
    * Add retries if control plane health check fails initially
    * Run all pre-install RBAC checks, instead of stopping at first failure
* Proxy / Proxy-Init
  * **Fixed** Fix routing issue when a pod makes a request to itself (#1585)
  * Only include `classification` label on `response_total` metric

## edge-18.11.1

* Proxy
  * **Fixed** Remove panic when failing to get remote address
  * **Improved** Better logging in TCP connect error messages
* Web UI
  * **Improved** Fixed a smattering of small UI issues

## edge-18.10.4

This release includes a major redesign of the web frontend to make use of the
Material design system. Additional features that leverage the new design are
coming soon! This release also includes the following changes:

* CLI
  * **Fixed** Fixed an issue with the `--registry` install flag not accepting
    hosts with ports (thanks, @alenkacz!)
* Web UI
  * **New** Added a new Grafana dashboard for authorities (thanks, @alpeb!)
  * **New** Revamped look and feel of the Linkerd dashboard by switching
    component libraries from antd to material-ui

## edge-18.10.3

* CLI
  * **New** Added an `--output` stat flag, for printing stats as JSON
  * **Improved** Updated the `top` table to set column widths dynamically
  * **Experimental** Added a `--single-namespace` install flag for installing
    the control plane with Role permissions instead of ClusterRole permissions
* Controller
  * Fixed a few issues with auto injection via the proxy-injector webhook:
    * Injected pods now execute the linkerd-init container last, to avoid
      rerouting requests during pod init
    * Original pod labels and annotations are preserved when auto-injecting
* Web UI
  * **New** Added a Help section in the sidebar containing useful links

## edge-18.10.2

This release brings major improvements to the CLI as described below, including
support for auto-injecting deployments via a Kubernetes Admission Controller.
Proxy auto-injection is **experimental**, and the implementation may change
going forward.

* CLI
  * **New** Added a `--proxy-auto-inject` flag to the `install` command,
    allowing for auto-injection of sidecar containers (Thanks @ihcsim!)
  * **Improved** Added `--proxy-cpu` and `--proxy-memory` flags to the `install`
    and `inject` commands, giving the ability to configure CPU + Memory requests
    (Thanks @benjdlambert!)
  * **Improved** Added a `--context` flag to specify the context to use to talk
    to the Kubernetes apiserver (Thanks @ffd2subroutine!)

## edge-18.10.1

* Web UI
  * **Improved** Tap and Top pages
    * Added clear button to query form
  * **Improved** Resource Detail pages
    * Limit number of resources shown in the graph
* Controller
  * CLI health check now uses unified endpoint for data plane checks
  * Include Licence files in all Docker images

Special thanks to @alenkacz for contributing to this release!

## edge-18.9.3

* Web UI
  * **Improved** Resource Detail page
    * Better rendering of the dependency graph at the top of the page
    * Unmeshed sources are now populated in the Inbound traffic table
    * Sources and destinations are aligned in the popover
  * **Improved** Tap and Top pages
    * Additional validation and polish for the form controls
    * The top table clears older results when a new top call is started
    * The top table now aggregates by HTTP method as well
* CLI
  * **New** The namespace in which Linkerd is installed is configurable via the
    `LINKERD_NAMESPACE` env var, in addition to the `--linkerd-namespace` flag
  * **New** The wait time for the `check` and `dashboard` commands is
    configurable via the `--wait` flag
  * **Improved** The `top` command now aggregates by HTTP method as well

Special thanks to @rochacon, @fahrradflucht and @alenkacz for contributing to
this release!

## stable-2.0.0

## edge-18.9.2

* **New** _edge_ and _stable_ release channels
* Web UI
  * **Improved** Tap & Top UIs with better layout and linking
* CLI
  * **Improved** `check --pre` command verifies the caller has sufficient
    permissions to install Linkerd
  * **Improved** `check` command verifies that Prometheus has data for proxied
    pods
* Proxy
  * **Fix** `hyper` crate dependency corrects HTTP/1.0 Keep-Alive behavior

## v18.9.1

* Web UI
  * **New** Default landing page provides namespace overview with expandable
    sections
  * **New** Breadcrumb navigation at the top of the dashboard
  * **Improved** Tap and Top pages
    * Table rendering performance improvements via throttling
    * Tables now link to resource detail pages
    * Tap an entire namespace when no resource is specified
    * Tap websocket errors provide more descriptive text
    * Consolidated source and destination columns
  * Misc ui updates
    * Metrics tables now include a small success rate chart
    * Improved latency formatting for seconds latencies
    * Renamed upstream/downstream to inbound/outbound
    * Sidebar scrolls independently from main panel, scrollbars hidden when not
      needed
    * Removed social links from sidebar
* CLI
  * **New** `linkerd check` now validates Linkerd proxy versions and readiness
  * **New** `linkerd inject` now provides an injection status report, and warns
    when resources are not injectable
  * **New** `linkerd top` now has a `--hide-sources` flag, to hide the source
    column and collapse top results accordingly
* Control Plane
  * Updated Prometheus to v2.4.0, Grafana to 5.2.4

## v18.8.4

* Web UI
  * **Improved** Tap and Top now have a better sampling rate
  * **Fixed** Missing sidebar headings now appear

## v18.8.3

* Web UI
  * **Improved** Kubernetes resource navigation in the sidebar
  * **Improved** resource detail pages:
    * **New** live request view
    * **New** success rate graphs
* CLI
  * `tap` and `top` have been improved to sample up to 100 RPS
* Control plane
  * Injected proxy containers now have readiness and liveness probes enabled

Special thanks to @sourishkrout for contributing a web readibility fix!

## v18.8.2

* CLI
  * **New** `linkerd top` command has been added, displays live traffic stats
  * `linkerd check` has been updated with additional checks, now supports a
    `--pre` flag for running pre-install checks
  * `linkerd check` and `linkerd dashboard` now support a `--wait` flag that
    tells the CLI to wait for the control plane to become ready
  * `linkerd tap` now supports a `--output` flag to display output in a wide
    format that includes src and dst resources and namespaces
  * `linkerd stat` includes additional validation for command line inputs
  * All commands that talk to the Linkerd API now show better error messages
    when the control plane is unavailable
* Web UI
  * **New** individual resources can now be viewed on a resource detail page,
    which includes stats for the resource itself and its nearest neighbors
  * **Experimental** web-based Top interface accessible at `/top`, aggregates
    tap data in real time to display live traffic stats
  * The `/tap` page has multiple improvements, including displaying additional
    src/dst metadata, improved form controls, and better latency formatting
  * All resource tables have been updated to display meshed pod counts, as well
    as an icon linking to the resource's Grafana dashboard if it is meshed
  * The UI now shows more useful information when server errors are encountered
* Proxy
  * The `h2` crate fixed a HTTP/2 window management bug
  * The `rustls` crate fixed a bug that could improperly fail TLS streams
* Control Plane
  * The tap server now hydrates metadata for both sources and destinations

## v18.8.1

* Web UI
  * **New** Tap UI makes it possible to query & inspect requests from the
    browser!
* Proxy
  * **New** Automatic, transparent HTTP/2 multiplexing of HTTP/1 traffic
    reduces the cost of short-lived HTTP/1 connections
* Control Plane
  * **Improved** `linkerd inject` now supports injecting all resources in a
    folder
  * **Fixed** `linkerd tap` no longer crashes when there are many pods
  * **New** Prometheus now only scrapes proxies belonging to its own linkerd
    install
  * **Fixed** Prometheus metrics collection for clusters with >100 pods

Special thanks to @ihcsim for contributing the `inject` improvement!

## v18.7.3

Linkerd2 v18.7.3 completes the rebranding from Conduit to Linkerd2, and improves
overall performance and stability.

* Proxy
  * **Improved** CPU utilization by ~20%
* Web UI
  * **Experimental** `/tap` page now supports additional filters
* Control Plane
  * Updated all k8s.io dependencies to 1.11.1

## v18.7.2

Linkerd2 v18.7.2 introduces new stability features as we work toward production
readiness.

* Control Plane
  * **Breaking change** Injected pod labels have been renamed to be more
    consistent with Kubernetes; previously injected pods must be re-injected
    with new version of linkerd CLI in order to work with updated control plane
  * The "ca-bundle-distributor" deployment has been renamed to "ca"
* Proxy
  * **Fixed** HTTP/1.1 connections were not properly reused, leading to
    elevated latencies and CPU load
  * **Fixed** The `process_cpu_seconds_total` was calculated incorrectly
* Web UI
  * **New** per-namespace application topology graph
  * **Experimental** web-based Tap interface accessible at  `/tap`
  * Updated favicon to the Linkerd logo

## v18.7.1

Linkerd2 v18.7.1 is the first release of the Linkerd2 project, which was
formerly hosted at github.com/runconduit/conduit.

* Packaging
  * Introduce new date-based versioning scheme, `vYY.M.n`
  * Move all Docker images to `gcr.io/linkerd-io` repo
* User Interface
  * Update branding to reference Linkerd throughout
  * The CLI is now called `linkerd`
* Production Readiness
  * Fix issue with destination service sending back incomplete pod metadata
  * Fix high CPU usage during proxy shutdown
  * ClusterRoles are now unique per Linkerd install, allowing multiple instances
    to be installed in the same Kubernetes cluster

## v0.5.0

Conduit v0.5.0 introduces a new, experimental feature that automatically
enables Transport Layer Security between Conduit proxies to secure
application traffic. It also adds support for HTTP protocol upgrades, so
applications that use WebSockets can now benefit from Conduit.

* Security
  * **New** `conduit install --tls=optional` enables automatic, opportunistic
    TLS. See [the docs][auto-tls] for more info.
* Production Readiness
  * The proxy now transparently supports HTTP protocol upgrades to support, for
    instance, WebSockets.
  * The proxy now seamlessly forwards HTTP `CONNECT` streams.
  * Controller services are now configured with liveness and readiness probes.
* User Interface
  * `conduit stat` now supports a virtual `authority` resource that aggregates
    traffic by the `:authority` (or `Host`) header of an HTTP request.
  * `dashboard`, `stat`, and `tap` have been updated to describe TLS state for
    traffic.
  * `conduit tap` now has more detailed information, including the direction of
    each message (outbound or inbound).
  * `conduit stat` now more-accurately records histograms for low-latency
    services.
  * `conduit dashboard` now includes error messages when a Conduit-enabled pod
    fails.
* Internals
  * Prometheus has been upgraded to v2.3.1.
  * A potential live-lock has been fixed in HTTP/2 servers.
  * `conduit tap` could crash due to a null-pointer access. This has been fixed.

[auto-tls]: docs/automatic-tls.md

## v0.4.4

Conduit v0.4.4 continues to improve production suitability and sets up internals
for the upcoming v0.5.0 release.

* Production Readiness
  * The destination service has been mostly-rewritten to improve safety and
    correctness, especially during controller initialization.
  * Readiness and Liveness checks have been added for some controller
    components.
  * RBAC settings have been expanded so that Prometheus can access node-level
    metrics.
* User Interface
  * Ad blockers like uBlock prevented the Conduit dashboard from fetching API
    data. This has been fixed.
  * The UI now highlights pods that have failed to start a proxy.
* Internals
  * Various dependency upgrades, including Rust 1.26.2.
  * TLS testing continues to bear fruit, precipitating stability improvements to
    dependencies like Rustls.

Special thanks to @alenkacz for improving docker build times!

## v0.4.3

Conduit v0.4.3 continues progress towards production readiness. It features a
new latency-aware load balancer.

* Production Readiness
  * The proxy now uses a latency-aware load balancer for outbound requests. This
    implementation is based on Finagle's Peak-EWMA balancer, which has been
    proven to significantly reduce tail latencies. This is the same load
    balancing strategy used by Linkerd.
* User Interface
  * `conduit stat` is now slightly more predictable in the way it outputs
    things, especially for commands like
    `watch conduit stat all --all-namespaces`.
  * Failed and completed pods are no longer shown in stat summary results.
* Internals
  * The proxy now supports some TLS configuration, though these features remain
    disabled and undocumented pending further testing and instrumentation.

Special thanks to @ihcsim for contributing his first PR to the project and to
@roanta for discussing the Peak-EWMA load balancing algorithm with us.

## v0.4.2

Conduit v0.4.2 is a major step towards production readiness. It features a wide
array of fixes and improvements for long-running proxies, and several new
telemetry features. It also lays the groundwork for upcoming releases that
introduce mutual TLS everywhere.

* Production Readiness
  * The proxy now drops metrics that do not update for 10 minutes, preventing unbounded
    memory growth for long-running processes.
  * The proxy now constrains the number of services that a node can route to
    simultaneously (default: 100). This protects long-running proxies from consuming
    unbounded resources by tearing down the longest-idle clients when the capacity is
    reached.
  * The proxy now properly honors HTTP/2 request cancellation.
  * The proxy could incorrectly handle requests in the face of some connection errors.
    This has been fixed.
  * The proxy now honors DNS TTLs.
  * `conduit inject` now works with `statefulset` resources.
* Telemetry
  * **New** `conduit stat` now supports the `all` Kubernetes resource, which
    shows traffic stats for all Kubernetes resources in a namespace.
  * **New** the Conduit web UI has been reorganized to provide namespace overviews.
  * **Fix** a bug in Tap that prevented the proxy from simultaneously satisfying more than
    one Tap request.
  * **Fix** a bug that could prevent stats from being reported for some TCP streams in
    failure conditions.
  * The proxy now measures response latency as time-to-first-byte.
* Internals
  * The proxy now supports user-friendly time values (e.g. `10s`) from environment
    configuration.
  * The control plane now uses client for Kubernetes 1.10.2.
  * Much richer proxy debug logging, including socket and stream metadata.
  * The proxy internals have been changed substantially in preparation for TLS support.

Special thanks to @carllhw, @kichristensen, & @sfroment for contributing to this release!

### Upgrading from v0.4.1

When upgrading from v0.4.1, we suggest that the control plane be upgraded to v0.4.2 before
injecting application pods to use v0.4.2 proxies.

## v0.4.1

Conduit 0.4.1 builds on the telemetry work from 0.4.0, providing rich,
Kubernetes-aware observability and debugging.

* Web UI
  * **New** Automatically-configured Grafana dashboards for Services, Pods,
    ReplicationControllers, and Conduit mesh health.
  * **New** `conduit dashboard` Pod and ReplicationController views.
* Command-line interface
  * **Breaking change** `conduit tap` now operates on most Kubernetes resources.
  * `conduit stat` and `conduit tap` now both support kubectl-style resource
    strings (`deploy`, `deploy/web`, and `deploy web`), specifically:
    * `namespaces`
    * `deployments`
    * `replicationcontrollers`
    * `services`
    * `pods`
* Telemetry
  * **New** Tap support for filtering by and exporting destination metadata. Now
    you can sample requests from A to B, where A and B are any resource or group
    of resources.
  * **New** TCP-level stats, including connection counts and durations, and
    throughput, wired through to Grafana dashboards.
* Service Discovery
  * The proxy now uses the [trust-dns] DNS resolver. This fixes a number of DNS
    correctness issues.
  * The destination service could sometimes return incorrect, stale, labels for an
    endpoint. This has been fixed!

[trust-dns]: https://github.com/bluejekyll/trust-dns

## v0.4.0

Conduit 0.4.0 overhauls Conduit's telemetry system and improves service discovery
reliability.

* Web UI
  * **New** automatically-configured Grafana dashboards for all Deployments.
* Command-line interface
  * `conduit stat` has been completely rewritten to accept arguments like `kubectl get`.
    The `--to` and `--from` filters can be used to filter traffic by destination and
    source, respectively.  `conduit stat` currently can operate on `Namespace` and
    `Deployment` Kubernetes resources. More resource types will be added in the next
    release!
* Proxy (data plane)
  * **New** Prometheus-formatted metrics are now exposed on `:4191/metrics`, including
    rich destination labeling for outbound HTTP requests. The proxy no longer pushes
    metrics to the control plane.
  * The proxy now handles `SIGINT` or `SIGTERM`, gracefully draining requests until all
    are complete or `SIGQUIT` is received.
  * SMTP and MySQL (ports 25 and 3306) are now treated as opaque TCP by default. You
    should no longer have to specify `--skip-outbound-ports` to communicate with such
    services.
  * When the proxy reconnected to the controller, it could continue to send requests to
    old endpoints. Now, when the proxy reconnects to the controller, it properly removes
    invalid endpoints.
  * A bug impacting some HTTP/2 reset scenarios has been fixed.
* Service Discovery
  * Previously, the proxy failed to resolve some domain names that could be misinterpreted
    as a Kubernetes Service name. This has been fixed by extending the _Destination_ API
    with a negative acknowledgement response.
* Control Plane
  * The _Telemetry_ service and associated APIs have been removed.
* Documentation
  * Updated [Roadmap](doc/roadmap.md)

Special thanks to @ahume, @alenkacz, & @xiaods for contributing to this release!

### Upgrading from v0.3.1

When upgrading from v0.3.1, it's important to upgrade proxies before upgrading the
controller. As you upgrade proxies, the controller will lose visibility into some data
plane stats. Once all proxies are updated, `conduit install |kubectl apply -f -` can be
run to upgrade the controller without causing any data plane disruptions. Once the
controller has been restarted, traffic stats should become available.

## v0.3.1

Conduit 0.3.1 improves Conduit's resilience and transparency.

* Proxy (data plane)
  * The proxy now makes fewer changes to requests and responses being proxied. In particular,
    requests and responses without bodies or with empty bodies are better supported.
  * HTTP/1 requests with different `Host` header fields are no longer sent on the same HTTP/1
    connection even when those hostnames resolve to the same IP address.
  * A connection leak during proxying of non-HTTP TCP connections was fixed.
  * The proxy now handles unavailable services more gracefully by timing out while waiting for an
    endpoint to become available for the service.
* Command-line interface
  * `$KUBECONFIG` with multiple paths is now supported. (PR #482 by @hypnoglow).
  * `conduit check` now checks for the availability of a Conduit update. (PR #460 by @ahume).
* Service Discovery
  * Kubernetes services with type `ExternalName` are now supported.
* Control Plane
  * The proxy is injected into the control plane during installation to improve the control plane's
    resilience and to "dogfood" the proxy.
  * The control plane is now more resilient regarding networking failures.
* Documentation
  * The markdown source for the documentation published at https://conduit.io/docs/ is now open
    source at https://github.com/runconduit/conduit/tree/master/doc.

## v0.3.0

Conduit 0.3 focused heavily on production hardening of Conduit's telemetry system. Conduit 0.3
should "just work" for most apps on Kubernetes 1.8 or 1.9 without configuration, and should support
Kubernetes clusters with hundreds of services, thousands of instances, and hundreds of RPS per
instance.

With this release, Conduit also moves from _experimental_ to _alpha_---meaning that we're ready
for some serious testing and vetting from you. As part of this, we've published the
[Conduit roadmap](https://conduit.io/roadmap/), and we've also launched some new mailing lists:
[conduit-users](https://groups.google.com/forum/#!forum/conduit-users),
[conduit-dev](https://groups.google.com/forum/#!forum/conduit-dev), and
[conduit-announce](https://groups.google.com/forum/#!forum/conduit-announce).

* CLI
  * CLI commands no longer depend on `kubectl`
  * `conduit dashboard` now runs on an ephemeral port, removing port 8001 conflicts
  * `conduit inject` now skips pods with `hostNetwork=true`
  * CLI commands now have friendlier error messages, and support a `--verbose` flag for debugging
* Web UI
  * All displayed metrics are now instantaneous snapshots rather than aggregated over 10 minutes
  * The sidebar can now be collapsed
  * UX refinements and bug fixes
* Conduit proxy (data plane)
  * Proxy does load-aware (P2C + least-loaded) L7 balancing for HTTP
  * Proxy can now route to external DNS names
  * Proxy now properly sheds load in some pathological cases when it cannot route
* Telemetry system
  * Many optimizations and refinements to support scale goals
  * Per-path and per-pod metrics have been removed temporarily to improve scalability and stability;
    they will be reintroduced in Conduit 0.4 (#405)
* Build improvements
  * The Conduit docker images are now much smaller.
  * Dockerfiles have been changed to leverage caching, improving build times substantially

Known Issues:
* Some DNS lookups to external domains fail (#62, #155, #392)
* Applications that use WebSockets, HTTP tunneling/proxying, or protocols such as MySQL and SMTP,
  require additional configuration (#339)

## v0.2.0

This is a big milestone! With this release, Conduit adds support for HTTP/1.x and raw TCP traffic,
meaning it should "just work" for most applications that are running on Kubernetes without
additional configuration.

* Data plane
  * Conduit now transparently proxies all TCP traffic, including HTTP/1.x and HTTP/2.
    (See caveats below.)
* Command-line interface
  * Improved error handling for the `tap` command
  * `tap` also now works with HTTP/1.x traffic
* Dashboard
  * Minor UI appearance tweaks
  * Deployments now searchable from the dashboard sidebar

Caveats:
* Conduit will automatically work for most protocols. However, applications that use WebSockets,
  HTTP tunneling/proxying, or protocols such as MySQL and SMTP, will require some additional
  configuration. See the [documentation](https://conduit.io/adding-your-service/#protocol-support)
  for details.
* Conduit doesn't yet support external DNS lookups. These will be addressed in an upcoming release.
* There are known issues with Conduit's telemetry pipeline that prevent it from scaling beyond a
  few nodes. These will be addressed in an upcoming release.
* Conduit is still in alpha! Please help us by
  [filing issues and contributing pull requests](https://github.com/runconduit/conduit/issues/new).

## v0.1.3

* This is a minor bugfix for some web dashboard UI elements that were not rendering correctly.

## v0.1.2

Conduit 0.1.2 continues down the path of increasing usability and improving debugging and
introspection of the service mesh itself.

* Conduit CLI
  * New `conduit check` command reports on the health of your Conduit installation.
  * New `conduit completion` command provides shell completion.
* Dashboard
  * Added per-path metrics to the deployment detail pages.
  * Added animations to line graphs indicating server activity.
  * More descriptive CSS variable names. (Thanks @natemurthy!)
  * A variety of other minor UI bugfixes and improvements
* Fixes
  * Fixed Prometheus config when using RBAC. (Thanks @FaKod!)
  * Fixed `tap` failure when pods do not belong to a deployment. (Thanks @FaKod!)

## v0.1.1

Conduit 0.1.1 is focused on making it easier to get started with Conduit.

* Conduit can now be installed on Kubernetes clusters that use RBAC.
* The `conduit inject` command now supports a `--skip-outbound-ports` flag that directs Conduit to
  bypass proxying for specific outbound ports, making Conduit easier to use with non-gRPC or HTTP/2
  protocols.
* The `conduit tap` command output has been reformatted to be line-oriented, making it easier to
  parse with common UNIX command line utilities.
* Conduit now supports routing of non-fully qualified domain names.
* The web UI has improved support for large deployments and deployments that don't have any
  inbound/outbound traffic.

## v0.1.0

Conduit 0.1.0 is the first public release of Conduit.

* This release supports services that communicate via gRPC only. non-gRPC HTTP/2 services should
  work. More complete HTTP support, including HTTP/1.0 and HTTP/1.1 and non-gRPC HTTP/2, will be
  added in an upcoming release.
* Kubernetes 1.8.0 or later is required.
* kubectl 1.8.0 or later is required. `conduit dashboard` will not work with earlier versions of
  kubectl.
* When deploying to Minikube, Minikube 0.23 or 0.24.1 or later are required. Earlier versions will
  not work.
* This release has been tested using Google Kubernetes Engine and Minikube. Upcoming releases will
  be tested on additional providers too.
* Configuration settings and protocols are not stable yet.
* Services written in Go must use grpc-go 1.3 or later to avoid
  [grpc-go bug #1120](https://github.com/grpc/grpc-go/issues/1120).
