Add helm chart

[zeroalphat]

This PR adds the Helm chart for ofen.
The mechanism for releasing the Helm chart will be added in a separate PR.

[Copilot]

Pull Request Overview

This PR adds a complete Helm chart implementation for the Ofen Kubernetes controller, allowing users to deploy the application via Helm instead of just raw Kubernetes manifests. The changes include generating Helm templates from existing Kustomize configurations and updating resource naming conventions.

• Renamed service account and related RBAC resources from imageprefetch-controller to controller-manager for consistency
• Added comprehensive Helm chart under charts/ofen/ with configurable values, templates, and documentation
• Updated build tooling to generate Helm templates from Kustomize configurations using yq

Reviewed Changes

Copilot reviewed 21 out of 24 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
config/rbac/*.yaml	Renamed service account and RBAC resources to use consistent controller-manager naming
config/manager/*.yaml	Updated service account references and enabled leader election by default
config/kustomize-to-helm/	Added Kustomize overlays and components for Helm template generation
charts/ofen/	Complete Helm chart implementation with templates, values, documentation, and helper functions
cmd/imageprefetch-controller/main.go	Enabled leader election by default for high availability
Makefile	Added yq tool and targets for generating Helm templates from Kustomize configurations

[masa213f]

Sorry for the late review.

I think the PDB for the controller is necessary for actual operation. Please include PDB in helm as well.

[masa213f]

Similar labels are defined in multiple places. Is it possible to reduce the definitions?

[zeroalphat]

@masa213f
The labels are defined in both .../kustomization.yaml and _helpers.tpl. Am I correct in understanding that you want to use only the definitions from _helpers.tpl, like in the example below?

metadata:
  labels:
    {{- include "ofen.labels" . | nindent 4  }}

I looked into whether this was possible, but it seems difficult to add only the keys to the labels field using tools like yq or Kustomize. Therefore, consolidating them into a single source appears to be challenging.

[masa213f]

it seems difficult to add only the keys to the labels field using tools like yq or Kustomize.

Oh, that's right. Thank you for confirming.
The redundancy in charts/ofen/templates/configmap.yaml has been reduced, so that's sufficient.

[masa213f]

LGTM