feat(tracing): Add root owner labels to injected pods, V2

This is a roll-forward of #14578, albiet with a slightly different implementation. The original PR would fall back to direct metadata API calls when getting resources from the informer cache. This instead resyncs the informer when a resource cannot be found and tries again, skipping the direct metadata API entirely.

Original PR description:

Currently, we add a label that identifies the parent resource that a proxy is attached to, usually a deployment, statefulset, daemonset, etc. These are populated via `linkerd.io/proxy-<resource>`` annotations, with a different label for each parent resource.

There are a few deficiencies with the current implementation. Currently, the implementation is specialized to only built-in k8s resources, so things like argocd rollouts will not appear. Additionally it does not recurse beyond two levels, so any more levels of parenting will not be captured.

This adds a set of new labels, `linkerd.io/proxy-root-parent` and `linkerd.io/proxy-root-parent-kind`, and `linkerd.io/proxy-root-parent-group`, that identify the name and kind of the root parent of a proxy workload. It also correctly recurses to the true root resource, at least as far as cluster role permissions for the proxy injector permit.

Note that the proxy already consumes all of the pod labels via the downward API, so there's no changes required to the proxy injector templates.

Signed-off-by: Scott Fleener <[email protected]>

Author: sfleen

cli/cmd/testdata/inject-filepath/expected/injected_nginx.yaml

@@ -17,6 +17,9 @@ spec:
         linkerd.io/control-plane-ns: linkerd
         linkerd.io/proxy-deployment: nginx
         linkerd.io/workload-ns: ""
+        linkerd.io/proxy-root-parent: nginx
+        linkerd.io/proxy-root-parent-group: apps
+        linkerd.io/proxy-root-parent-kind: Deployment
     spec:
       containers:
       - env:

cli/cmd/testdata/inject-filepath/expected/injected_nginx_redis.yaml

@@ -16,6 +16,9 @@ spec:
         app: redis
         linkerd.io/control-plane-ns: linkerd
         linkerd.io/proxy-deployment: redis
+        linkerd.io/proxy-root-parent: redis
+        linkerd.io/proxy-root-parent-group: apps
+        linkerd.io/proxy-root-parent-kind: Deployment
         linkerd.io/workload-ns: ""
     spec:
       containers:
@@ -270,6 +273,9 @@ spec:
         app: nginx
         linkerd.io/control-plane-ns: linkerd
         linkerd.io/proxy-deployment: nginx
+        linkerd.io/proxy-root-parent: nginx
+        linkerd.io/proxy-root-parent-group: apps
+        linkerd.io/proxy-root-parent-kind: Deployment
         linkerd.io/workload-ns: ""
     spec:
       containers:

cli/cmd/testdata/inject-filepath/expected/injected_redis.yaml

@@ -17,6 +17,9 @@ spec:
         linkerd.io/control-plane-ns: linkerd
         linkerd.io/proxy-deployment: redis
         linkerd.io/workload-ns: ""
+        linkerd.io/proxy-root-parent: redis
+        linkerd.io/proxy-root-parent-group: apps
+        linkerd.io/proxy-root-parent-kind: Deployment
     spec:
       containers:
       - env: