Respect HTTP proxies when rendering Guardian policy

[pasanw]

Description

The operator will inspect the tigera-guardian pod to determine if a proxy is in use, and update egress policy rules accordingly.

The proxy environment variables are read from the Guardian pod as it is expected they are injected via a mutating admission webhook on the pod spec.

The approach limits to amount of queries done for pods, in anticipation of pods no longer being cached by the operator. The query for pods is only made when the cluster-connection controller has observed a new availability condition and that condition indicates that the deployment is available.

For PR author

• Tests for change.
• If changing pkg/apis/, run make gen-files
• If changing versions, run make gen-versions

For PR reviewers

A note for code reviewers - all pull requests must have the following:

• Milestone set according to targeted release.
• Appropriate labels:
  • kind/bug if this is a bugfix.
  • kind/enhancement if this is a a new feature.
  • enterprise if this PR applies to Calico Enterprise only.

[rene-dekker]

Needs formatting