[Overvability] Add Grafana dashboard for karmada-apiserver component

[jabellard]

What type of PR is this?

/kind feature

What this PR does / why we need it:

Which issue(s) this PR fixes:

Fixes #

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Does this PR introduce a user-facing change?:

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[gemini-code-assist]

Summary of Changes

Hello @jabellard, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request significantly enhances the observability of the karmada-apiserver by adding a dedicated Grafana dashboard. This new dashboard provides a holistic view of the API server's operational state, covering critical performance indicators, request patterns, and underlying resource utilization, allowing for more effective monitoring and troubleshooting.

Highlights

• New Grafana Dashboard: Introduced a comprehensive Grafana dashboard specifically for monitoring the karmada-apiserver component, enhancing observability.
• Detailed Metrics: The dashboard provides a wide array of metrics, including API server performance, request latency, error rates, request mix, payload sizes, admission/audit/watch events, etcd interactions, and Go runtime statistics.
• Improved Observability: This addition enables users to gain deeper insights into the health, performance, and operational characteristics of the Karmada API server.

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[gemini-code-assist]

Code Review

This pull request introduces a new Grafana dashboard for the karmada-apiserver component, along with accompanying README files. The dashboard provides valuable insights into the apiserver's performance and health.

My review focuses on ensuring consistency and correctness. I've pointed out a bug in a PromQL query for the version panel that would cause it to fail, and suggested using the karmada_build_info metric for consistency with other Karmada components. I've also made minor suggestions to add missing newlines to the new markdown files.

[gemini-code-assist]

This PromQL query is incorrect. The kubernetes_build_info metric uses a gitVersion label (camelCase), but the query attempts to group by git_version (snake_case). This will cause the panel to fail to display the version information.

For consistency with other Karmada components like karmada-controller-manager, please use the karmada_build_info metric, which correctly uses the git_version label. If karmada-apiserver does not yet expose this metric, it should be updated to do so. This change will improve monitoring consistency across the project.

Additionally, the extra spaces in the query should be removed for cleanliness.

Suggested change

	"expr": "sum by (git_version) ( kubernetes_build_info{})",
	"expr": "sum by (git_version) (karmada_build_info{})",

[gemini-code-assist]

Please add a newline at the end of the file to adhere to common file formatting conventions.

Suggested change

	This directory contains Grafana dashboards for monitoring and visualizing the operational state of Karmada components.
	This directory contains Grafana dashboards for monitoring and visualizing the operational state of Karmada components.

[gemini-code-assist]

Please add a newline at the end of the file to adhere to common file formatting conventions.

Suggested change

	Insights for Karmada API server.
	Insights for Karmada API server.

[jabellard]

Hey @RainbowMango. Lately, I've been doing a lot of work to enhance observability for our managed multi-cluster platform built on top of Karmada, and will be sharing some of the dashboards I've built with the community. This is the first. I will have more coming!

[codecov-commenter]

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Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 45.64%. Comparing base (10a5f0f) to head (6825aa6).
⚠️ Report is 18 commits behind head on master.
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Additional details and impacted files

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Flag	Coverage Δ
unittests	45.64% <ø> (-0.23%)	⬇️

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[zhzhuang-zju]

This is the first. I will have more coming!

@jabellard That looks great! Could we use an issue to track and document these tasks?

[RainbowMango]

Thanks @jabellard, interesting. But I don't get how to run it if I want to explore it on my side. Are you going to add more guides or demonstrate at the community meeting?

[jabellard]

Thanks @jabellard, interesting. But I don't get how to run it if I want to explore it on my side. Are you going to add more guides or demonstrate at the community meeting?

Hey @RainbowMango. I've been building dashboards to enhance observability for our managed Karmada platform and will be sharing some of them with the community. The ones I have shared so far are ready for use, but with the assumption that a Prometheus stack has already been setup and is scraping metrics from the Karmada control plane component pods.

I'd love to show these dashboards in action on our managed Karmada platform, but unfortunately can't present internal systems without approval. I will be submitting a proposal for KubeCon EU Observability Day to showcase that work. I'm exited about that and will share the proposal with you soon.

For now, here's what I can do:

• Create a new script or extend one of the existing scripts (e.g., hack/local_up_karmada.sh) to install the Kube Prom stack in a host Kind cluster
• Configure scraping of metrics for the control plane components of a Karmada isntance running in that host cluster
• Import the Grafana dashboards
• Show the dashboards in action at a community meeting

What do you think?

/cc @zhzhuang-zju

[zhzhuang-zju]

@jabellard Thank you for your detailed response and for looking forward to the proposal.

Create a new script or extend one of the existing scripts (e.g., hack/local_up_karmada.sh) to install the [Kube Prom stack](https://github.com/prometheus-community/helm-charts/tree/main/charts/kube-prometheus-stack) in a host Kind cluster

I prefer creating a new script that installs the Kube Prom stack to a cluster where Karmada is already installed. This approach would make the script more versatile. For other matters, I don't have any issues, but I believe we need a comprehensive guide covering the entire process from installation to getting Grafana up and running. I noticed that you've documented a documentation task in issue #6852, which is great.

[jabellard]

@jabellard Thank you for your detailed response and for looking forward to the proposal.

Create a new script or extend one of the existing scripts (e.g., hack/local_up_karmada.sh) to install the [Kube Prom stack](https://github.com/prometheus-community/helm-charts/tree/main/charts/kube-prometheus-stack) in a host Kind cluster

I prefer creating a new script that installs the Kube Prom stack to a cluster where Karmada is already installed. This approach would make the script more versatile. For other matters, I don't have any issues, but I believe we need a comprehensive guide covering the entire process from installation to getting Grafana up and running. I noticed that you've documented a documentation task in issue #6852, which is great.

Yeah. I can do that. @RainbowMango , thoughts?