Support json logging format

[huww98]

What type of PR is this?

/kind feature

What this PR does / why we need it:

Only one line of log is changed to structured logging, to prove the json format works. We can migrate others in the future.

Which issue(s) this PR fixes:

Fixes #

Special notes for your reviewer:

Like: kubernetes-csi/external-resizer#330

Related:

• Support json logging format external-provisioner#1318

Before:

I0228 16:17:28.677813   69383 main.go:169] Version: unknown
E0228 16:17:28.678324   69383 main.go:174] unable to load in-cluster configuration, KUBERNETES_SERVICE_HOST and KUBERNETES_SERVICE_PORT must be defined

After:

I0228 16:18:55.410566   69629 main.go:179] "Version" version="unknown"
E0228 16:18:55.410944   69629 main.go:184] unable to load in-cluster configuration, KUBERNETES_SERVICE_HOST and KUBERNETES_SERVICE_PORT must be defined

After and with --logging-format=json

{"ts":1740730756069.866,"caller":"snapshot-controller/main.go:179","msg":"Version","v":0,"version":"unknown"}
{"ts":1740730756070.206,"caller":"snapshot-controller/main.go:184","msg":"unable to load in-cluster configuration, KUBERNETES_SERVICE_HOST and KUBERNETES_SERVICE_PORT must be defined"}

Does this PR introduce a user-facing change?:

Add support for -logging-format=json
Remove klog specific flags according to KEP-2845

KEP-2845: Deprecate klog specific flags in Kubernetes Components

[k8s-ci-robot]

Hi @huww98. Thanks for your PR.

I'm waiting for a kubernetes-csi member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

I understand the commands that are listed here.

Details

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 kubernetes-sigs/prow repository.

[xing-yang]

/ok-to-test

[xing-yang]

Can you replace "KEP-2845" in the release notes with a description of what that feature is about?
Also add "KEP-2845" and a link to the KEP in the PR description itself.

[huww98]

Can you replace "KEP-2845" in the release notes with a description of what that feature is about?

Actually already included, that is "Remove klog specific flags". KEP-2845 is just offering more context to the interested reader of the release note. kubernetes-csi/external-resizer#411 contains some more discussion about this change.

Also add "KEP-2845" and a link to the KEP in the PR description itself.

Done

[huww98]

@xing-yang Rebased. I think this is the only CSI sidecar that don't support json logging now. Can we merge this so that we can use json logging for the whole CSI driver?

[xing-yang]

In the PR description, can you add output of the logs before and after your change?

[huww98]

In the PR description, can you add output of the logs before and after your change?

Done

[xing-yang]

/lgtm
/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: huww98, xing-yang

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Details

Needs approval from an approver in each of these files:

• OWNERS [xing-yang]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment