How to handle experiment of Helm charts in OCI repos when 3.0.0 comes out


Matt Farina
 

One of the features being developed for Helm v3 is the ability to store Helm charts in OCI container image repositories (by following the distribution spec). You can think of these as repositories like Docker Hub, Quay, Azure Container Registry, and others. But, the distribution spec was designed for images rather than other artifacts which some, including more than Helm, are trying to put in there now. Work has been ongoing with the OCI to work out the best way to store these artifacts but it isn't complete and won't be complete in time to push out the 3.0.0. We don't want to delay the 3.0.0 for this feature so we are looking for feedback on some of the options we have discussed.

The options we are looking at are:

1) To document the feature as experimental in the CLI and in the documentation. Breaking changes may (likely?) happen to support the final implementation. It would not fall under Helms use of SemVer until it is no longer an experiment. We would likely not expose it via the usage information until it was ready.

2) Move the OCI integration into a plugin that would need to be installed. It would be hosted under the Helm org on GitHub. Once it is ready it would be added to Helm v3 as part of a feature release.

Note, just because Helm would be able to push and pull charts from repositories does not mean all repositories will support it. Many public repositories white list the artifacts they will store. Until Helm is added to the white list it would not work. Some repositories are not following the distribution spec and may run into issues. As use grows we hope more repositories support charts.

If you have feedback on either of the two paths we would appreciate it.

Regards,
Matt Farina

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