fix: update kube version requirement to 1.21

[NierYYDS]

The controller depends on the v1 version of EndpointSlice, but the discovery.k8s.io/v1 API was first introduced in Kubernetes version 1.21.

What this PR does / why we need it:

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• CVE Report (Scanner found CVE and adding report)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation only

Which issue/s this PR fixes

How Has This Been Tested?

Checklist:

• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I've read the CONTRIBUTION guide
• I have added unit and/or e2e tests to cover my changes.
• All new and existing tests passed.

[k8s-ci-robot]

Hi @NierYYDS. Thanks for your PR.

I'm waiting for a kubernetes 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.

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/test-infra repository.

[netlify]

✅ Deploy Preview for kubernetes-ingress-nginx canceled.

Name	Link
🔨 Latest commit	fdc2a63
🔍 Latest deploy log	https://app.netlify.com/sites/kubernetes-ingress-nginx/deploys/6620ef40ee23690008139643

[NierYYDS]

Error got from controller

W0418 07:19:52.793210       7 reflector.go:539] k8s.io/[email protected]/tools/cache/reflector.go:229: failed to list *v1.EndpointSlice: the server could not find the requested resource
E0418 07:19:52.793283       7 reflector.go:147] k8s.io/[email protected]/tools/cache/reflector.go:229: Failed to watch *v1.EndpointSlice: failed to list *v1.EndpointSlice: the server could not find the requested resource

[longwuyuan]

@NierYYDS thanks for catching this. Good catch

https://kubernetes.io/docs/reference/using-api/deprecation-guide/#endpointslice-v125

@rikatz @tao12345666333 @Gacko @strongjz this needs to go in before controller v1.10.1. Please review/approve

/triage accepted
/priority important-soon
/kind bug

[longwuyuan]

/ok-totest

[longwuyuan]

@NierYYDS the requirement of K8S v1.21.1 is met by the current value of '>=1.20.0-0', so please indicate where it will break, to explicit justifiy the change proposed

[longwuyuan]

And now we have to figure out if someone explicitly uses port 30090 instead of allowing random portnumber picking or is this a flake etc (error seen in CI)

Error: INSTALLATION FAILED: Service "ingress-nginx-eaugyxlswn-controller" is invalid: spec.ports[2].nodePort: Invalid value: 30090: provided port is already allocated

[strongjz]

/retest
/ok-to-test
/priority backlog
/triage accepted

[Gacko]

/lgtm

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: Gacko, NierYYDS

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

The pull request process is described here

Needs approval from an approver in each of these files:

• charts/ingress-nginx/OWNERS [Gacko]

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

[Gacko]

/cherry-pick release-1.10

[k8s-infra-cherrypick-robot]

@Gacko: once the present PR merges, I will cherry-pick it on top of release-1.10 in a new PR and assign it to you.

In response to this:

/cherry-pick release-1.10

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/test-infra repository.

[k8s-infra-cherrypick-robot]

@Gacko: new pull request created: #11279

In response to this:

/cherry-pick release-1.10

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/test-infra repository.

[NierYYDS]

@NierYYDS the requirement of K8S v1.21.1 is met by the current value of '>=1.20.0-0', so please indicate where it will break, to explicit justifiy the change proposed

@longwuyuan
I encountered this error because I deployed latest version 1.10.0 of the controller on a Kubernetes cluster with version 1.20.
Initially, I deployed this chart based on the requirements mentioned in the helm doc without thoroughly verifying version compatibility.

[longwuyuan]

thanks. The PR is merged AFAIK