Remove useless nodeip calls and deprecate --force-namespace-isolation

[alexkursell]

What this PR does / why we need it: We were making a useless call to get the node information for our pod, information which was then never used. This is normally fine, but when the permissions do not exist to access node info, this caused an error. (see #3817)

Which issue this PR fixes: fixes #3817

Special notes for your reviewer:

There is still one condition where ingress-nginx needs to get the node info (to get the external IP address): when neither --publish-service nor --publish-status-address are set. It doesn't look like the same information can't be retrieved from the pod object, so it looks like this use needs to be kept around. Would it be better to just document the fact that without either of these two flags, we must make cluster level API calls, or would it be better to keep the --force-namespace-isolation flag and make creating an ingress-nginx instance with --force-namespace-isolation but neither --publish-service nor --publish-status-address an error?

[aledbf]

@alexkursell please don't remove the GetNodeIPOrName method. This is used in beremetal and scenarios like minikube. Maybe the call to that function could be ommited if the flags --publish-service or --publish-status-address are used.

[aledbf]

/hold

[alexkursell]

@alexkursell please don't remove the GetNodeIPOrName method. This is used in beremetal and scenarios like minikube. Maybe the call to that function could be ommited if the flags --publish-service or --publish-status-address are used.

I didn't remove the method, but calling it and storing the result in PodInfo doesn't seem to do anything. I can't find anywhere where that field is accessed.

[aledbf]

I didn't remove the method, but calling it and storing the result in PodInfo doesn't seem to do anything.

Sorry, you are right. The method is called and used only as the last resource in the status update.

[aledbf]

@alexkursell please squash the commits and this lgtm

[aledbf]

/lgtm
/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: aledbf, alexkursell

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:

• OWNERS [aledbf]

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