metrics: support multi-k8s in grafana dashboards

[just1900]

Signed-off-by: just1900 legendj228@gmail.com

What problem does this PR solve?

Issue Number: ref #4129

Problem Summary:

K8s community and organizations are increasingly deploying multiple Kubernetes clusters to improve availability, isolation and scalability. Since TiDB Operator have support deploying tidb across-kubernetes, this PR will address the multi-k8s issue without affecting existing single-cluster use case.

What is changed and how it works?

What's Changed:

• add a k8s_cluster label in all expr
• add k8s_cluster variable in Grafana templating

How it works:

• For users with single-k8s, nothing need to be changed, just use it as before.
• For users with multi-k8s:
  • first add kubernetes label to identify k8s cluster in your prometheus' external_labels.
  • set field "hide" to '0' to show variables in grafana via sed -i s/"hide": 2/"hide": 0/g <path/to/dashboard.json>
  • load it to grafana

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)
• No code

Side effects

• Performance regression: Consumes more CPU
• Performance regression: Consumes more Memory
• Breaking backward compatibility

Documentation

• Affects user behaviors
• Contains syntax changes
• Contains variable changes
• Contains experimental features
• Changes MySQL compatibility

Release note

metrics: support multi-k8s in grafana dashboards

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• JaySon-Huang
• flowbehappy

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[flowbehappy]

/merge

[ti-chi-bot]

@flowbehappy: It seems you want to merge this PR, I will help you trigger all the tests:

/run-all-tests

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[ti-chi-bot]

@flowbehappy: /merge in this pull request requires 2 approval(s).

In response to this:

/merge

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the ti-community-infra/tichi repository.

[sre-bot]

Coverage for changed files

no c/c++ source change detected

Coverage summary

Functions  MissedFunctions  Executed  Lines   MissedLines  Cover
16755      9447             43.62%    188616  95709        49.26%

full coverage report (for internal network access only)

[JaySon-Huang]

/merge

[ti-chi-bot]

@JaySon-Huang: It seems you want to merge this PR, I will help you trigger all the tests:

/run-all-tests

You only need to trigger /merge once, and if the CI test fails, you just re-trigger the test that failed and the bot will merge the PR for you after the CI passes.

If you have any questions about the PR merge process, please refer to pr process.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the ti-community-infra/tichi repository.

[ti-chi-bot]

@JaySon-Huang: /merge in this pull request requires 2 approval(s).

In response to this:

/merge

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the ti-community-infra/tichi repository.

[flowbehappy]

/merge

[ti-chi-bot]

@flowbehappy: It seems you want to merge this PR, I will help you trigger all the tests:

/run-all-tests

You only need to trigger /merge once, and if the CI test fails, you just re-trigger the test that failed and the bot will merge the PR for you after the CI passes.

If you have any questions about the PR merge process, please refer to pr process.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the ti-community-infra/tichi repository.

[ti-chi-bot]

This pull request has been accepted and is ready to merge.

Commit hash: c5dac82

[sre-bot]

Coverage for changed files

no c/c++ source change detected

Coverage summary

Functions  MissedFunctions  Executed  Lines   MissedLines  Cover
16755      9447             43.62%    188616  95710        49.26%

full coverage report (for internal network access only)

[sre-bot]

Coverage for changed files

no c/c++ source change detected

Coverage summary

Functions  MissedFunctions  Executed  Lines   MissedLines  Cover
16755      9447             43.62%    188616  95710        49.26%

full coverage report (for internal network access only)

[just1900]

@JaySon-Huang Could you please help add the cherrypick label to 5.0 5.1 5.2 5.3 5.4👀?

[ti-chi-bot]

In response to a cherrypick label: new pull request created: #4206.