Metrics are enabled by default for ingress-nginx

[mitulshah-suse]

What happened:

Metrics are enabled by default in the controller code.
https://github.com/kubernetes/ingress-nginx/blob/main/pkg/flags/flags.go#L177
But the chart by default disables it.
https://github.com/kubernetes/ingress-nginx/blob/main/charts/ingress-nginx/values.yaml#L861

What you expected to happen:

As a result of the above there is a flag --enable-metrics=false which gets added.
Intuitively removing that flag should keep the metrics disabled, but it gets enabled instead, which seems like unwanted behaviour.
Ideally, both default values should be false, and end user can enable it if needed. Or at least both should be true if that is the expected default value for ingress-nginx.

NGINX Ingress controller version (exec into the pod and run nginx-ingress-controller --version.):

1.11.2

[k8s-ci-robot]

This issue is currently awaiting triage.

If Ingress contributors determines this is a relevant issue, they will accept it by applying the triage/accepted label and provide further guidance.

The triage/accepted label can be added by org members by writing /triage accepted in a comment.

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.

[longwuyuan]

/remove-kind bug

This is not a bug. All user requirements are not identical and hence there is always going to be options. Most users have to tune the install to their requirement.

[mitulshah-suse]

@longwuyuan while i agree that the users would install as per their requirement, if we install the controller using a manifest, we get metrics enabled, but with the chart we get it disabled. I believe its better to have both of them in sync.
In fact until this PR was merged in 1.10 #10959, both the controller and chart were in sync and were enabling it by default. (though i suppose it was unintentional)

[Gacko]

Actually I didn't want to change the default. Metrics have been disabled in the chart by default for even longer, but we never passed the according argument to the controller, so inside the controller they were always enabled even if they were disabled in the chart and therefore not accessible.

So my PR only ensures they are really disabled if requested by the chart.