Fixes#3444Fixes#3443
## Background and Behavior
This change adds support for the destination service to resolve Get requests which contain a service clusterIP or pod ip as the `Path` parameter. It returns the stream of endpoints, just as if `Get` had been called with the service's authority. This lays the groundwork for allowing the proxy to TLS TCP connections by allowing the proxy to do destination lookups for the SO_ORIG_DST of tcp connections. When that ip address corresponds to a service cluster ip or pod ip, the destination service will return the endpoints stream, including the pod metadata required to establish identity.
Prior to this change, attempting to look up an ip address in the destination service would result in a `InvalidArgument` error.
Updating the `GetProfile` method to support ip address lookups is out of scope and attempts to look up an ip address with the `GetProfile` method will result in `InvalidArgument`.
## Implementation
We do this by creating a `IPWatcher` which wraps the `EndpointsWatcher` and supports lookups by ip. `IPWatcher` maintains a mapping up clusterIPs to service ids and translates subscriptions to an IP address into a subscription to the service id using the underlying `EndpointsWatcher`.
Since the service name is no longer always infer-able directly from the input parameters, we restructure `EndpointTranslator` and `PodSet` so that we propagate the service name from the endpoints API response.
## Testing
This can be tested by running the destination service locally, using the current kube context to connect to a Kubernetes cluster:
```
go run controller/cmd/main.go destination -kubeconfig ~/.kube/config
```
Then lookups can be issued using the destination client:
```
go run controller/script/destination-client/main.go -path 192.168.54.78:80 -method get -addr localhost:8086
```
Service cluster ips and pod ips can be used as the `path` argument.
Signed-off-by: Alex Leong <alex@buoyant.io>
Followup to #2990, which refactored `linkerd endpoints` to use the
`Destination.Get` API instead of the `Discovery.Endpoints` API, leaving
the Discovery with no implented methods. This PR removes all the Discovery
code leftovers.
Fixes#3499
* Set custom cluster domain in GetServiceProfileFor
* Set custom cluster domain in tap server
Move fetching cluster domain for tap server to cmd main
* Handle fetchting cluster domain errors separately
* Use custom cluster domain for traffic split adaptor
Signed-off-by: Armin Buerkle <armin.buerkle@alfatraining.de>
In preparation for #3242, the destination controller will need to
support a broader set of valid authorities including IP addresses.
This change modifies the destination controller's authority-parsing code
so that the is-this-a-kubernete-service-name decision is decoupled from
parsing of authorities into their consituent parts.
The `Get` API now explicitly handles IP address names, though it
currently fails all such resolutions.
Fixes https://github.com/linkerd/linkerd2/issues/2800#issuecomment-513740498
When the Linkerd proxy sends a query for a Kubernetes external name service to the destination service, the destination service returns `NoEndpoints: exists=false` because an external name service has no endpoints resource. Due to a change in the proxy's fallback logic, this no longer causes the proxy to fallback to either DNS or SO_ORIG_DST and instead fails the request. The net effect is that Linkerd fails all requests to external name services.
We change the destination service to instead return `InvalidArgument` for external name services. This causes the proxy to fallback to SO_ORIG_DST instead of failing the request.
Signed-off-by: Alex Leong <alex@buoyant.io>
We add support for looking up individual pods in a stateful set with the destination service. This allows Linkerd to correctly proxy requests which address individual pods. The authority structure for such a request is `<pod-name>.<service>.<namespace>.svc.cluster.local:<port>`.
Fixes#2266
Signed-off-by: Alex Leong <alex@buoyant.io>
This change implements the DstOverrides feature of the destination profile API (aka traffic splitting).
We add a TrafficSplitWatcher to the destination service which watches for TrafficSplit resources and notifies subscribers about TrafficSplits for services that they are subscribed to. A new TrafficSplitAdaptor then merges the TrafficSplit logic into the DstOverrides field of the destination profile.
Signed-off-by: Alex Leong <alex@buoyant.io>
This is a major refactor of the destination service. The goals of this refactor are to simplify the code for improved maintainability. In particular:
* Remove the "resolver" interfaces. These were a holdover from when our decision tree was more complex about how to handle different kinds of authorities. The current implementation only accepts fully qualified kubernetes service names and thus this was an unnecessary level of indirection.
* Moved the endpoints and profile watchers into their own package for a more clear separation of concerns. These watchers deal only in Kubernetes primitives and are agnostic to how they are used. This allows a cleaner layering when we use them from our gRPC service.
* Renamed the "listener" types to "translator" to make it more clear that the function of these structs is to translate kubernetes updates from the watcher to gRPC messages.
Signed-off-by: Alex Leong <alex@buoyant.io>
This change reintroduces identity hinting to the destination service.
The Get endpoint includes identities for pods that are injected with an
identity-mode of "default" and have the same linkerd control plane.
A `serviceaccount` label is now also added to destination response
metadata so that it's accessible in prometheus and tap.
This change introduces a new Identity service implementation for the
`io.linkerd.proxy.identity.Identity` gRPC service.
The `pkg/identity` contains a core, abstract implementation of the service
(generic over both the CA and (Kubernetes) Validator interfaces).
`controller/identity` includes a concrete implementation that uses the
Kubernetes TokenReview API to validate serviceaccount tokens when
issuing certificates.
This change does **NOT** alter installation or runtime to include the
identity service. This will be included in a follow-up.
The proxy's TLS implementation has changed to use a new _Identity_ controller.
In preparation for this, the `--tls=optional` CLI flag has been removed
from install and inject; and the `ca` controller has been deleted. Metrics
and UI treatments for TLS have **not** been removed, as they will continue to
be valuable for the new Identity system.
With the removal of the old identity scheme, the Destination service's proxy
ID field is now set with an opaque string (e.g. `ns:emojivoto`) to enable
locality awareness.
linkerd/linkerd2#2349 removed the `--single-namespace` flag, in favor of
runtime detection of cluster vs. namespace access, and also
ServiceProfile availability. This maintained control-plane support for
running in these two states.
This change requires control-plane components have cluster-wide
Kubernetes API access and ServiceProfile availability, and will error
out if not. Once #2349 merges, stage 1 install will be a requirement for
a successful stage 2 install.
Part of #2337
Signed-off-by: Andrew Seigner <siggy@buoyant.io>
As described in #2217, the controller returns TLS identities for results even
when the destination pod may not be able to participate in identity
requester: specifically, the other pod may not have the same controller
namespace or it may not be injected with identity.
This change introduces a new annotation, linkerd.io/identity-mode that is set
when injecting pods (via both CLI and webhook). This annotation is always
added.
The destination service now only returns TLS identities when this annotation
is set to optional on a pod and the destination pod uses the same controller.
These semantics are expected to change before the 2.3 release.
Fixes#2217
The control-plane components relied on a `--single-namespace` param,
passed from `linkerd install` into each individual component, to
determine which namespaces they were authorized to access, and whether
to support ServiceProfiles. This command-line flag was redundant given
the authorization rules encoded in the parent `linkerd install` output,
via [Cluster]Role[Binding]s.
Modify the control-plane components to query Kubernetes at startup to
determine which namespaces they are authorized to access, and whether
ServiceProfile support is available. This allows removal of the
`--single-namespace` flag on the components.
Also update `bin/test-cleanup` to cleanup the ServiceProfile CRD.
TODO:
- Remove `--single-namespace` flag on `linkerd install`, part of #2164
Signed-off-by: Andrew Seigner <siggy@buoyant.io>
Up until now, the proxy-api controller service has been the sole service
that the proxy communicates with, implementing the majoriry of the API
defined in the `linkerd2-proxy-api` repo. But this is about to change:
linkerd/linkerd2-proxy-api#25 introduces a new Identity service; and
this service must be served outside of the existing proxy-api service
in the linkerd-controller deployment (so that it may run under a
distinct service account).
With this change, the "proxy-api" name becomes less descriptive. It's no
longer "the service that serves the API for the proxy," it's "the
service that serves the Destination API to the proxy." Therefore, it
seems best to bite the bullet and rename this to be the "destination"
service (i.e. because it only serves the
`io.linkerd.proxy.destination.Destination` service).
Co-authored-by: Kevin Lingerfelt <kl@buoyant.io>
Signed-off-by: Kevin Lingerfelt <kl@buoyant.io>
Alex Leong
Alejandro Pedraza
arminbuerkle
Oliver Gould
Andrew Seigner
Kevin Lingerfelt