Helm v3 and namespaces considerations

[alpeb]

We decided not honoring Helm's --namespace option because it would make helm install create the namespace itself without the metadata we require and it would also fail when it attempts to create it again when it stumbles across our namespace.yaml template.

That was for v2. In Helm v3 --namespace doesn't attempt to create the namespace. Users are expected to use a separate tool for that, and if the namespace is not already there then helm install will fail (it doesn't even get to the point of namespace.yaml unlike above with v2).

If the user doesn't use --namespace in v3 then linkerd will get properly installed in the linkerd namespace, but the secret used by Helm to keep track of the release (now that Tiller is gone) will live in the default namespace. I'm not sure how can that affect tightly restricted clusters.

I just wanted for us to be aware of this new behavior in v3. If we wanted to support --namespace we'd have to remove namespace.yaml from the chart and provide instructions on how to generate the namespace beforehand with the appropriate metadata.

[alpeb]

Closing for now, as there are no actionable items for Helm v2. Might revisit when v3 comes out, and after user feedback.