[grafana] Add control plane metrics dashboard (identity, proxy-injector, destination)

[bezarsnba]

What problem are you trying to solve?

While Linkerd provides some Grafana dashboards out of the box, it currently lacks a dashboard that covers metrics related to the control plane components — namely identity, proxy injector, and target. These components emit critical operational metrics (such as certificate update events and proxy injection admission responses) that are exposed by Prometheus, but I haven’t found them in official dashboards yet.

This lack makes it difficult for users to monitor the health and behavior of the control plane, identify issues (such as failed injections or expired certificates) early, or effectively troubleshoot unexpected behavior during runtime.

How should the problem be solved?

I created a new Grafana dashboard that visualizes key metrics from the Linkerd control plane components (identity, proxy-injector, and destination). It includes panels for metrics such as proxy_inject_admission_responses_total, identity_cert_refresh_count, identity_cert_expiration_timestamp_seconds, control_response_total, and control_response_latency_ms_bucket.

The goal is to provide better visibility into the health and performance of the control plane. I propose adding this dashboard to the existing grafana/ directory to complement the current dashboards and make it easier for users to monitor these components out of the box.

Screenshot:

Any alternatives you've considered?

N/A

How would users interact with this feature?

N/A

Would you like to work on this feature?

yes