Add pod annotations

[estenrye]

Proposed changes

This change refactors pod annotations to allow a user to add arbitrary annotations to pods.

Problem: The helm chart provided no means to annotate pods to allow them to be meshed in a LinkerD service mesh.

Solution: Added a new helm value that allows the user to provide arbitrary pod annotations

Testing:

Template with default values.yaml manifest

helm template foo . | yq 'select(.kind == "Deployment") | .spec.template.metadata'

Result

labels:
  app.kubernetes.io/name: nginx-gateway-fabric
  app.kubernetes.io/instance: foo
annotations:
  prometheus.io/scrape: "true"
  prometheus.io/port: "9113"

Template with default values and set pod annotations.

helm template foo . --set nginxGateway.podAnnotations."linkerd\.io/inject"="enabled" | yq 'select(.kind == "Deployment") | .spec.template.metadata'

Result

labels:
  app.kubernetes.io/name: nginx-gateway-fabric
  app.kubernetes.io/instance: foo
annotations:
  linkerd.io/inject: enabled
  prometheus.io/scrape: "true"
  prometheus.io/port: "9113"

Checklist

Before creating a PR, run through this checklist and mark each as complete.

• I have read the CONTRIBUTING doc
• I have added tests that prove my fix is effective or that my feature works
• I have checked that all unit tests pass after adding my changes
• I have updated necessary documentation
• I have rebased my branch onto main
• I will ensure my PR is targeting the main branch and pulling from my branch from my own fork