Flag to disable Leader Election Feature on Nginx Controller

[msfidelis]

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

fixes #8919

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.

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: msfidelis / name: Matheus Fidelis (16afa03)

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[k8s-ci-robot]

Hi @msfidelis. Thanks for your PR.

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[rikatz]

/check-cla
/ok-to-test

[strongjz]

Please add an e2e test with the leader election set to false.

Also, I like the idea of making that configurable as well, the leader election TTL. Can you add that and make the default 30 seconds?

ingress-nginx/internal/ingress/controller/status.go

Lines 117 to 124 in c85765a

	ttl := 30 * time.Second
	elector, err := leaderelection.NewLeaderElector(leaderelection.LeaderElectionConfig{
	Lock: &lock,
	LeaseDuration: ttl,
	RenewDeadline: ttl / 2,
	RetryPeriod: ttl / 4,

[rikatz]

/triage accepted
/priority backlog
/kind feature

[strongjz]

/triage accepted
/kind feature

[strongjz]

--leader-election-enabled default true.

[cpanato]

some comment, overall looks good

[cpanato]

Same

[rikatz]

Ok, so:

• e2e tests seems to work fine 🥳 just remove all of the comments and unused variables (keep the file clean). BTW, great approach on having 2 ingresses and testing both!
• @strongjz maybe we can do the leader election timeout on another PR, up to you and @msfidelis but as this was a "good first issue" I'm worried about overloading it. We will not be able to really e2e test the leader election timeout with some fancy "kill pod, wait it to change to another pod name, etc", so I think we can do it as a follow up (it is going to be a fun e2e test to write tho).
• @msfidelis now we need to fix the helm docs, which should be just running helm docs make (or something like that, my memory is bad, I'm getting old).

Other than the points above, I think it is already fine to move. @strongjz I would just avoid cherry-picking this as it is not a bug, but a feature

/approve
/hold

Will wait for some other reviewers + the fixes I've asked before lgtm'ing and unholding

[strongjz]

That's fine for a follow-up.

Do we still want it to be a positive config option?

I'm on mobile right now so idk why helm docs is upset.

[cpanato]

helm doc needs to be updated

+| controller.disableLeaderElection | bool | `false` | This configuration disable Nginx Controller Leader Election Defaults to false |

[cpanato]

also need to fix the lint

[lint: test/e2e/disableleaderelection/disable_leader.go#L28](https://github.com/kubernetes/ingress-nginx/pull/11064/files#annotation_18883045317)
var `cfgOK` is unused (unused)

[msfidelis]

Hello @strongjz ! Thank you for your attention and for the review. I think these suggestions would be very interesting. What you thing if I submitted these new TTL feature for Leader Election in a smaller and more focused PR?

Please add an e2e test with the leader election set to false.

Also, I like the idea of making that configurable as well, the leader election TTL. Can you add that and make the default 30 seconds?

ingress-nginx/internal/ingress/controller/status.go

Lines 117 to 124 in c85765a

	ttl := 30 * time.Second
	elector, err := leaderelection.NewLeaderElector(leaderelection.LeaderElectionConfig{
	Lock: &lock,
	LeaseDuration: ttl,
	RenewDeadline: ttl / 2,
	RetryPeriod: ttl / 4,

[msfidelis]

Hello @cpanato and @rikatz !! Thank you very much for the support. It's an honor for me to be able to count on you at this time.

I have made the lint corrections, helm-docs and add more unit and e2e tests.

[rikatz]

/lgtm
/approve
@cpanato leaving for you to remove the hold

@msfidelis thank you very much for your contribution

[cpanato]

/lgtm /approve @cpanato leaving for you to remove the hold

@msfidelis thank you very much for your contribution

i was about to do the same 😂

/honk

[k8s-ci-robot]

@cpanato:

In response to this:

/lgtm /approve @cpanato leaving for you to remove the hold

@msfidelis thank you very much for your contribution

i was about to do the same 😂

/honk

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[cpanato]

thanks for this PR

/lgtm
/unhold

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: cpanato, msfidelis, rikatz

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