Scale down of aws-custom-route-controller

[elchead]

How to categorize this PR?

/area control-plane
/kind bug
/platform aws

What this PR does / why we need it:

Which issue(s) this PR fixes:
Fixes #628

Special notes for your reviewer:

Release note:

[gardener-robot]

@elchead Labels area/todo, kind/todo do not exist.

[gardener-robot]

@elchead Thank you for your contribution.

[gardener-robot-ci-3]

Thank you @elchead for your contribution. Before I can start building your PR, a member of the organization must set the required label(s) {'reviewed/ok-to-test'}. Once started, you can check the build status in the PR checks section below.

[elchead]

e2e tested

[kon-angelo]

/invite @ialidzhikov @MartinWeindel

[MartinWeindel]

Thanks, looks good to me.
I have only one small change request. There is another test case named "should return correct control plane chart values (k8s >= 1.18)" (valuesprovider_test.go, line 296ff). Can you check here for replicas = 0?

[kon-angelo]

/reviewed ok-to-test

[elchead]

@MartinWeindel i am doing this already see l.257 in the definition of crcChartValues

[DockToFuture]

Didn't know that there was a PR open on this, just discovered it. Did the same thing in my code to remove the overlay but also checked if the UseCustomRouteController field is nil and then disabled the awsRouteController. This will keep it disabled for existing clusters as long as they specify no overlay.

	awsCustomRouteControllerEnabled := false
	replicas := extensionscontroller.GetControlPlaneReplicas(cluster, scaledDown, 1)
	if cpConfig.CloudControllerManager != nil &&
		cpConfig.CloudControllerManager.UseCustomRouteController != nil {
		awsCustomRouteControllerEnabled = true
	}
	if awsCustomRouteControllerEnabled && !*cpConfig.CloudControllerManager.UseCustomRouteController {
		replicas = 0
	}

	values := map[string]interface{}{
		"enabled":     awsCustomRouteControllerEnabled,
		"replicas":    replicas,
...

Do you prefer to enable the aws route controller always or only for clusters which have the UseCustomRouteController field specified?

[kon-angelo]

@DockToFuture AFAIK, the problem is that without setting the enabled field the replica update won't be propagated because the chart will not be applied.

Ideally, we would be able to discern if the chart had already been applied at least once (hence there was a CRC running at some point) and only then apply the replicas, but I think this complicates the flow. Since we want to support disabling CRC and effectively setting replicas to 0 (since we don't delete the deployment), why not have only this case to care about.

[DockToFuture]

@DockToFuture AFAIK, the problem is that without setting the enabled field the replica update won't be propagated because the chart will not be applied.

Sure without setting the enabled field the chart won't be applied. If we want to keep it like this im fine with it. Can we get it merged then I will rebase my PR on this.

[DockToFuture]

/lgtm

[kon-angelo]

/lgtm

[MartinWeindel]

/lgtm