Issue when trying to run flux-local diff on helm-charts from private Gitlab repo

[j-veen]

Hello, I've created this ticket because we are running into some issues when trying to run a flux-local diff on a helmRelease that uses a helm-chart from our own private Gitlab-repo hosted on gitlab.com
The command we try to run is: flux-local --log-level DEBUG diff hr <helmrelease-name> -n <namespace> --path gcp-toolkit/clusters/development/ --branch-orig rdgcp-183-deploy-flux

After running that command we see the error below:

flux_local.exceptions.HelmException: Command 'helm template <helmrelease-name> flux-system-<helmrepo-name>/<helmchart-name> --namespace <namespace> --repository-cache /tmp/tmpre7syfz8 --repository-config /tmp/tmpii474bk2/repository-config.yaml --registry-config /tmp/tmp5qvh56qy.json --skip-crds --skip-tests --version 1.2.0 --values /tmp/tmpii474bk2/values.yaml' failed with return code 1
Error: no cached repo found. (try 'helm repo update'): open /tmp/tmpre7syfz8/flux-system-<helmchart-name>-index.yaml: no such file or directory

flux-local error:  Command 'helm template <helmrelease-name> flux-system-<helmrepo-name>/<helmchart-name> --namespace <namespace> --repository-cache /tmp/tmpre7syfz8 --repository-config /tmp/tmpii474bk2/repository-config.yaml --registry-config /tmp/tmp5qvh56qy.json --skip-crds --skip-tests --version 1.2.0 --values /tmp/tmpii474bk2/values.yaml' failed with return code 1
Error: no cached repo found. (try 'helm repo update'): open /tmp/tmpre7syfz8/flux-system-<helmchart-name>-index.yaml: no such file or directory

Our helmrelease and helmRepo looks as follows:

---
apiVersion: helm.toolkit.fluxcd.io/v2
kind: HelmRelease
metadata:
  name: <helmrelease-name>
  namespace: <namespace>
spec:
  interval: 2m
  chart:
    spec:
      chart: <helm-chart name>
      version: '1.2.0'
      sourceRef:
        kind: HelmRepository
        name: <helmrepo name>
        namespace: flux-system
      interval: 10m
  values:

---
apiVersion: source.toolkit.fluxcd.io/v1
kind: HelmRepository
metadata:
  name: <helmrepo-name>
  namespace: flux-system
spec:
  interval: 5m
  url: https://gitlab.com/api/v4/projects/<project-id>/packages/helm/stable
  secretRef:
    name: gitlab-deploy-helm-dev-token

I've added the helm-repo to my local helm installation, so I would think that it should be able to pull the helm-chart.
Hoping that you are able to help us out.

[allenporter]

I believe this is a duplicate of #857 which has some history.

[j-veen]

I've tried reading through that issue and I don't fully understand what the conclusion is.
We currently push our charts to a Gitlab repo using cm-push, which indicates to me that the Gitlab repo uses ChartMuseum under the hood.
Is it just ChartMuseum that isn't supported by flux-local and would pushing our chart to OCI possible fix the issue, or is the issue that private-repo's that require authentication are not supported.