Roll out new unified standards to all Flux controllers

[scottrigby]

• Part of Define and unify Flux controller standards #1602
• Depends on Document runtime package and APIs, provide additional helpers pkg#117
• Depends on Document abstract outline of package in fluxcd/pkg/runtime directory pkg#118

Status

Now that fluxcd/pkg#101 is merged, people who have already contributed to Flux controllers built on controller-runtime (and have sufficient knowledge of K8s API conventions) can already start. Until fluxcd/pkg#117 is merged, we can do this on other controllers by pinning that PR branch from the source controller (refactor-reconcilers), and then after merge change back to main, and when available, to a tagged revision post-merge.

Tasks

In PRIORITY order, with linked issues/PRs where applicable, and current status:

• Update kustomize-controller to new unified standards 🎉 (Roll out new unified standards to Kustomize Controller kustomize-controller#663)
• source-controller https://github.com/fluxcd/flux2/issues/1679 🙂 (Implement helpers from pkg/runtime source-controller#361)
• helm-controller Update helm-controller to new unified standards helm-controller#303 in progress ⏳
• Update image-automation-controller to new unified standards
• Update image-reflector-controller to new unified standards
• Update notification-controller to new unified standards

Nice to have:

• Update Example controller to new unified standards #1625 on hold 🚫

[hiddeco]

RC releases for all relevant packages have been published:

Package	Version	Reference
github.com/fluxcd/pkg/apis/kustomize	v0.3.0-rc.1	Link
github.com/fluxcd/pkg/apis/meta	v0.11.0-rc.1	Link
github.com/fluxcd/pkg/runtime	v0.13.0-rc.5	Link