A few small improvements to our docker build scripts:
* Centralized the list of docker images to a DOCKER_IMAGES variable defined in _docker.sh
* Build scripts now honor the TAG variable, if defined
* Unused docker-images script has been removed
We also update the `--control-plane-version` Linkerd install flag to affect the policy controller version as well.
Taken together, this enables the following workflow for building and deploying changes to individual Linkerd components. For example, suppose you wish to deploy changes which only affect the controller image:
```console
# Begin by building all images at main with a dev tag
> TAG=alex-dev bin/docker-build
# OR begin by retagging all images from a recent release
> bin/docker-retag-all edge-21.8.4 alex-dev
# Make changes and then rebuild specific component
> TAG=alex-dev bin/docker-build-controller
# Load images into kind
> TAG=alex-dev bin/image-load --kind --cluster alex
# Install Linkerd
> bin/linkerd install --control-plane-version alex-dev --proxy-version alex-dev | k apply -f -
```
Signed-off-by: Alex Leong <alex@buoyant.io>
The name `proxy-mutator` is too generic. In particular, several different linkerd extensions will have mutating webhooks which mutate the proxy sidecar, the MutatingWebhookConfiguration resource is cluster scoped, and each one needs a unique name.
We use the `jaeger-injector` name instead. This gives us a pattern to follow for future webhooks as well (e.g. `tap-injector` etc.)
Signed-off-by: Alex Leong <alex@buoyant.io>
* Jaeger injector mutating webhook
Closes#5231. This is based off of the `alex/sep-tracing` branch.
This webhook injects the `LINKERD2_PROXY_TRACE_COLLECTOR_SVC_ADDR`,
`LINKERD2_PROXY_TRACE_COLLECTOR_SVC_NAME` and
`LINKERD2_PROXY_TRACE_ATTRIBUTES_PATH` environment vars into the proxy
spec when a pod is created, as well as the podinfo volume and its mount.
If any of these are found to be present already in the pod spec, it
exits without applying a patch.
The `values.yaml` file has been expanded to include config for this
webhook. In particular, one can define a `namespaceSelector` and/or a
`objectSelector` to filter which pods will this webhook act on.
The config entries in `values.yam` for `collectorSvcAddr` and
`collectorSvcAccount` can be overriden with the
`config.linkerd.io/trace-collector` and
`config.alpha.linkerd.io/trace-collector-service-account` annotation at
the namespace or pod spec level.
## How to test:
```bash
docker build . -t ghcr.io/linkerd/jaeger-webhook:0.0.1 -f
jaeger/proxy-mutator/Dockerfile
k3d image import ghcr.io/linkerd/jaeger-webhook:0.0.1
bin/helm-build
linkerd install
helm install jaeger jaeger/charts/jaeger
linkerd inject https://run.linkerd.io/emojivoto.yml | kubectl apply -f -
kubectl -n emojivoto get po -l app=emoji-svc -oyaml | grep -A1 TRACE
```
## Reinvocation policy
The webhookconfig resource is configured with `reinvocationPolicy:
IfNeeded` so that if the tracing injector gets triggered before the
proxy injector, it will get triggered a second time after the proxy
injector runs so it can act on the injected proxy. By default this won't
be necessary because the webhooks run in alphabetical order (this is not
documented in k8s docs though) so
`linkerd-proxy-injector-webhook-config` will run before
`linkerd-proxy-mutator-webhook-config`. In order to test the
reinvocation mechanism, you can change the name of the former so it gets
called first.
I versioned the webhook image as `0.0.1`, but we can decide to align
that with linkerd's main version tag.
Alex Leong
Alejandro Pedraza