Are there any problems using helm 2 and helm 3 in parallel?

Question

Are there any problems when using helm 2 and helm 3 in parallel - on the same cluster?

Reason behind is, that the Terraform helm provider is still NOT available for helm 3. But with another application we'd like to proceed with helm 3.

Have you maybe tried this? Or did you run into some problems?

Answer 1

Helm 2 and Helm 3 can be installed concurrently to manage the same cluster. This works when Helm 2 uses ConfigMaps for storage as Helm 3 uses Secrets for storage. There is however a conflict when Helm 2 uses Secrets for storage and stores the release in the same namespace as the release. The conflict occurs because Helm 3 uses different tags and ownership for the secret objects that Helm 2 does. It can therefore try to create a release that it thinks does not exist but will fail then because Helm 2 already has a secret with that name in that namespace.

Additionally, Helm 2 can be migrated to enable Helm 3 to manage releases previously handled by Helm 2 ref. https://github.com/helm/helm-2to3. This also works when Helm 2 uses ConfigMaps for storage as Helm 3 uses Secrets for storage. There is a conflict again however when using secrets because of the same naming convention. A possible solution around this would be for Helm 3 to use a different naming convention for release versions.

Answer 2

There is no problem using them in parallel. However, you need to treat them somehow like separate tools, meaning that Helm 3 won't list (or anyhow manage) your releases from Helm 2 and vice versa.