Add webhook health check

[sbueringer]

/kind feature

Describe the solution you'd like
It would be nice if the controller health checks would use the readiness of the webhook server (instead of the no-op Ping).

For reference, the implementation in cluster-api: kubernetes-sigs/cluster-api#4989

Anything else you would like to add:
This requires at least controller-runtime v0.9.3.

Environment:

• cluster-api-provider-azure version:
• Kubernetes version: (use kubectl version):
• OS (e.g. from /etc/os-release):

[CecileRobertMichon]

Note: This controller-runtime health check is only available since v0.9.3

this means we first need a new version of CAPI.

[sbueringer]

@CecileRobertMichon Just out of curiosity. Why do you need a new CAPI version to upgrade controller-runtime?

[CecileRobertMichon]

I guess we don't need to. Historically we've updated controller-runtime as part of CAPI updates, since CAPI defined the minimum version, but we could use a later patch, as long as we're on v0.9.x.

Whoever takes this on would have to first update the controller-runtime version in go.mod to v0.9.3.

/good-first-issue

[k8s-ci-robot]

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In response to this:

I guess we don't need to. Historically we've updated controller-runtime as part of CAPI updates, since CAPI defined the minimum version, but we could use a later patch, as long as we're on v0.9.x.

Whoever takes this on would have to first update the controller-runtime version in go.mod to v0.9.3.

/good-first-issue

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[jayesh-srivastava]

Hi. I am a new contributor and I would like to work on this issue. Can you please guide me through this? It would be a great help to me. Also, can I assign the issue to myself?

[devigned]

@jayesh-srivastava have you had an opportunity to review the link @sbueringer helpfully added above, kubernetes-sigs/cluster-api#4989? That link shows why and what needs to be applied in this repo. If you still have questions after reviewing, please let us know.

[jayesh-srivastava]

@devigned Yeah I saw that link. A little overwhelming because I am a new contributor, can you please just guide me as to where to start from?

[devigned]

The gist of what is happening in the 8 lines of the other PR is that a health check is added to the main.go to ensure the controller's webhooks have started. The same thing needs to happen in this repo.

[jayesh-srivastava]

Okay okay, I understood. Thanks @devigned . Will try to resolve this issue.

[sbueringer]

There was an error found in the healthcheck. The fix PR is already merged in controller-runtime, but we should wait until the next controller-runtime version is released (0.9.6) with adding it to CAPZ.

xref:

• Slack discussion: https://kubernetes.slack.com/archives/CD6U2V71N/p1627643594012600
• bugfix PR: 🐛 0.9: fix webhook health check tls handshake timeout errors controller-runtime#1616

[sbueringer]

fyi controller-runtime v0.9.6 has been released with a fix. So we should be good to go (I also verified it via the e2e tests of the cluster-api repo).

[ThorstenHans]

/assign