Configure chart commands to use helm clients for OCI and private regi…

[ethanchowell]

Configure chart commands to use helm clients for OCI and private registry support

Please check below, if the PR fulfills these requirements:

• Commit(s) and code follow the repositories guidelines.
• Test(s) have been added or updated to support these change(s).
• Doc(s) have been added or updated to support these change(s).

Associated Links:

Types of Changes:

This PR extends the chart implementation to use the existing helm install mechanics for chart resolution, primarily to support using OCI references and local repository.yaml configs needed for accessing private registries. With these changes, users can define their chart manifests like

apiVersion: content.hauler.cattle.io/v1alpha1
kind: Charts
metadata:
  name: hauler-content-charts-example
spec:
  charts:
    # fetch helm chart
    - name: rancher
      repoURL: https://releases.rancher.com/server-charts/stable
    - name: rancher
      repoURL: rancher-stable # From `helm repo add rancher-stable https://releases.rancher.com/server-charts/stable`
      version: 2.8.2
    - name: nginx
      repoURL: oci://registry-1.docker.io/bitnamicharts

Proposed Changes:

Verification/Testing of Changes:

Create a chart manifest using oci registries and hauler sync -f oci-hauler.yaml

apiVersion: content.hauler.cattle.io/v1alpha1
kind: Charts
metadata:
  name: hauler-content-charts-example
spec:
  charts:
    - name: nginx
      repoURL: oci://registry-1.docker.io/bitnamicharts

Or with hauler store add chart nginx --repo "oci://registry-1.docker.io/bitnamicharts"

For local repositories resolution create another file using a local repo alias and hauler sync -f aliased-hauler.yaml

apiVersion: content.hauler.cattle.io/v1alpha1
kind: Charts
metadata:
  name: hauler-content-charts-example
spec:
  charts:
    - name: rancher
      repoURL: rancher-stable

or `hauler store add chart rancher --repo rancher-stable

Additional Context:

I recently ran into some issues trying to pull charts from a private registry, which I have a local repositories.yaml file configured for. It makes sense why using the repoURL: https://my-private-repo would 401, but hauler is unable to use the local repositories.yaml config I have which make it difficult to use locally and in CI. Using the helm mechanics though, this config gets read under the hood and as a result picks up OCI support basically for free.

[zackbradys]

Thanks for the contribution @ethanchowell! Great to have folks extending features and functionalities within hauler.

[zackbradys]

LGTM!! 👍