--namespace is ignored by "helm template"

[jpetazzo]

What I do:

helm template --repo https://helm.github.io/examples hello-world --namespace hello

What I expect:

The generated YAML has namespace: hello

What I see instead:

The generated YAML doesn't have any namespace information

Current workaround:

helm template --repo https://helm.github.io/examples hello-world \
| kubectl create -f- -o yaml --dry-run=client --namespace hello

Output of helm version:

version.BuildInfo{Version:"v3.8.0", GitCommit:"d14138609b01886f544b2025f5000351c9eb092e", GitTreeState:"clean", GoVersion:"go1.17.6"}

This is kind of related to #9813 (but also not quite :)).

If this is not meant to be supported, perhaps using the --namespace flag with helm template could throw an error and suggest the workaround shown above?

[hickeyma]

As @bacongobbler stated in #9813 (comment), "helm template is not expected to interact with a cluster - its only job is to load a chart, render its templates with the provided values, and display the output."

This flag should be removed also but it will have to wait until Helm 4 for backward compatibility.

[bacongobbler]

The —namespace flag affects the value of {{ .Release.Namespace }}. I think there’s value keeping that flag around.

This seems more related to #3553. I gave an explanation why helm does not inject a namespace into the template here: #3553 (comment)

[jpetazzo]

Would it be worth it to issue a warning when the --namespace flag is used with helm template or would that also be lots of effort for not much gain?