Helm-operator: Install charts from OCI registries

[fredgate]

Describe the feature
A Helm chart can be stored

• on a repository like chartmuseum
• on a registry supporting the OCI format

Helm operator can install charts from a Helm repository.
Helm 3 now starts to support OCI format, as an experimental feature. Even if the installation is for the moment not as easy as a helm install myrelease myrepository/mychart command, it can be done in few steps :

• helm registry login myregistry.io
• helm chart pull myregistry.io/mychart:1.0.0
• helm chart export myregistry.io/mychart:1.0.0
• helm install myrelease ./my-chart

It would be nice if Helm operator could do these steps to deploy an OCI chart.
OCI is the future for Helm charts, and OCI registries allow to store all cloud artefacts in one place. For example, Harbor support OCI format since recent 2.0 version.

What would the new user story look like?

1. What are the prerequisites for this?
   Operator must be configured to use Helm 3.

2. User starts up the operator using the --add-frobnication flag
   No new flag is required.

3. A new HelmRelease is applied
   Helm operator could install charts in both formats, OCI and chartmuseum. The indication could be indicated in the spec of the HelmRelease definition.
   For a chart in chartmuseum format, we could keep the actual definition :

spec:
  releaseName: myrelease
  chart:
    repository: https://myrepository.io
    name: mychart
    version: 1.0.0

For a chart in OCI format the definition could replace repository attribute with a registry attribute :

spec:
  releaseName: myrelease
  chart:
    registry: https://myregistry.io
    name: mychart
    version: 1.0.0

1. Deployments happen, which include frobnication
   Deployment is identical for the two formats.

[seaneagan]

@hiddeco while this technically could be supported in the helm operator, it is helm 3 only and still experimental there, so guessing it makes more sense to move to source-controller repo for helm-controller to eventually consume?

[hiddeco]

This is correct. Another problem is that most of the API was still in internal last time I checked. Making it hard if not impossible for us to provide such a feature until they make it publicly available.

[cep21]

Hi, did this support get merged in?

[lebenitza]

@hiddeco do you think OCI support will be added here or should we look forward for flux2 helm controller?

• https://toolkit.fluxcd.io/components/helm/controller/

With this, a lot of infrastructure and flows can be simplified.

More here: https://github.com/helm/helm/issues/8259

[stefanprodan]

Here is the OCI issue for Flux2: https://github.com/fluxcd/source-controller/issues/124

Closing this as helm-op is in maintenance mode and no new features will be added.