[For Reference] Example of adding a new API and Controller

[caseydavenport]

Description

This is an example PR to show rougly the changes necessary to add the skeleton for a new API and Controller.

NOTE

• This example adds a namespaced resource. If you want to use a global resource (like most of our operator APIs), specify --namespaced=false on step 1.

The commits are broken down and show precisely which commands were run.
Specifically:

1. Generate the new Resource and controller skeleton

   operator-sdk create api --group=operator.tigera.io --version=v1 --kind=DemoResource --resource --controller 
   

2. Generate manifests

   make manifests 
   

3. Add a new Reconciler to pkg/controller, and point the internal/controller implementation at it.

The next steps here would be to fill out the Add and Reconcile functions in pkg/controller/demoresource/demoresource_controller.go with the specific logic of the new feature.

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.

[electricjesus]

Love it.. what version of operator-sdk should I use for this? If we have a specific version that works with our PROJECT file maybe we could consider a dockerized version as a makefile target perhaps?