* Inject preStop hook into the proxy sidecar container to stop it last
This commit adds support for a Graceful Shutdown technique that is used
by some Kubernetes administrators while the more perspective
configuration is being discussed in
https://github.com/kubernetes/kubernetes/issues/65502
The problem is that RollingUpdate strategy does not guarantee that all
traffic will be sent to a new pod _before_ the previous pod is removed.
Kubernetes inside is an event-driven system and when a pod is being
terminating, several processes can receive the event simultaneously.
And if an Ingress Controller gets the event too late or processes it
slower than Kubernetes removes the pod from its Service, users requests
will continue flowing into the black whole.
According [to the documentation](https://kubernetes.io/docs/concepts/workloads/pods/pod/#termination-of-pods)
> 1. If one of the Pod’s containers has defined a `preStop` hook,
> it is invoked inside of the container. If the `preStop` hook is still
> running after the grace period expires, step 2 is then invoked with
> a small (2 second) extended grace period.
>
> 2. The container is sent the `TERM` signal. Note that not all
> containers in the Pod will receive the `TERM` signal at the same time
> and may each require a preStop hook if the order in which
> they shut down matters.
This commit adds support for the `preStop` hook that can be configured
in three forms:
1. As command line argument `--wait-before-exit-seconds` for
`linkerd inject` command.
2. As `linkerd2` Helm chart value `Proxy.WaitBeforeExitSeconds`.
2. As `config.alpha.linkerd.io/wait-before-exit-seconds` annotation.
If configured, it will add the following preHook to the proxy container
definition:
```yaml
lifecycle:
preStop:
exec:
command:
- /bin/bash
- -c
- sleep {{.Values.Proxy.WaitBeforeExitSeconds}}
```
To achieve max benefit from the option, the main container should have
its own `preStop` hook with the `sleep` command inside which has
a smaller period than is set for the proxy sidecar. And none of them
must be bigger than `terminationGracePeriodSeconds` configured for the
entire pod.
An example of a rendered Kubernetes resource where
`.Values.Proxy.WaitBeforeExitSeconds` is equal to `40`:
```yaml
# application container
lifecycle:
preStop:
exec:
command:
- /bin/bash
- -c
- sleep 20
# linkerd-proxy container
lifecycle:
preStop:
exec:
command:
- /bin/bash
- -c
- sleep 40
terminationGracePeriodSeconds: 160 # for entire pod
```
Fixes#3747
Signed-off-by: Eugene Glotov <kivagant@gmail.com>
Handling of whitespace paths was not fully implemented; this patch adds
the missing pieces. Also, only use bash where bash-specific
functionality is used/needed.
Signed-off-by: Joakim Roubert <joakimr@axis.com>
This PR begins to migrate Conduit to Linkerd2:
* The proxy has been completely removed from this repo, and is now located at
github.com/linkerd/linkerd2-proxy.
* A `Dockerfile-proxy` has been added to fetch the most-recently published proxy
binary from build.l5d.io.
* Proxy-specific protobuf bindings have been moved to
github.com/linkerd/linkerd2-proxy-api.
* All docker images now use the gcr.io/linkerd-io registry.
* `inject` now uses `LINKERD2_PROXY_` environment variables
* Go paths have been updated to reflect the new (future) repo location.
The build scripts assume they are executed from the root of this repo.
This prevents running scripts from other locations, for example,
`cd web && ../bin/go-run .`.
Modify the build scripts to work regardless of current directory.
Fixes#301
Signed-off-by: Andrew Seigner <siggy@buoyant.io>
DOCKER_FORCE_BUILD, combined with symbolic tags, added complexity and
risk of running unintended versions of the code.
This change removes DOCKER_FORCE_BUILD, and sets all Docker tags
programmatically. The decision to pull or build has been moved up the
stack from _docker.sh to the docker-build-* scripts. Workflows that
want to favor docker pulls (like ci), can do so explicitly via
docker-pull.
fixes#141
Signed-off-by: Andrew Seigner <andrew@sig.gy>
We’ve built Conduit from the ground up to be the fastest, lightest,
simplest, and most secure service mesh in the world. It features an
incredibly fast and safe data plane written in Rust, a simple yet
powerful control plane written in Go, and a design that’s focused on
performance, security, and usability. Most importantly, Conduit
incorporates the many lessons we’ve learned from over 18 months of
production service mesh experience with Linkerd.
This repository contains a few tightly-related components:
- `proxy` -- an HTTP/2 proxy written in Rust;
- `controller` -- a control plane written in Go with gRPC;
- `web` -- a UI written in React, served by Go.
Eugene Glotov
Joakim Roubert
陈谭军
Oliver Gould
Andrew Seigner