Migrate to Kubebuilder v3

[danehans]

Please describe the problem you have
The operator was bootstrapped using kubebuilder v2 and should consider migrating to v3. Reference the migration guide for additional details.

cc: @BostjanBozic

[BostjanBozic]

I have been fiddling around a bit, checking how to approach this. My question is, should we try and follow new scaffolded structure/parameters as much as possible or do we just adjust PROJECT file? Some examples:

• scaffolded manager deployment manifest has health-probe-bind-address flag, should we add it to contour-operator.go?
• Makefile as quite some changes, e.g. testing is now performed on a fly using temp downloaded binaries for etcd
• container name of operator is manager, in our case it is contour-operator

I checked codebase and apart from PROJECT file and some of the naming/structural changes, everything is already upgraded (e.g. Reconcile function is already inline with v3, CRDs are already on apiextensions.k8s.io/v1).

[youngnick]

It seems like if we want to be able to use kubebuilder's CLI tooling, we will need to follow the scaffolded structure as much as possible. That seems like a slightly better plan to me.