Namespaced templates

[urbaman]

Hi,

I added the namespace metadata to all namespaced resourced, managed valkey.namespace in helpers, and added namespaceOverride value to override the default.

[lindhe]

I'm so glad to see this PR!

In Kustomize <5.8.1, there was a bug (kubernetes-sigs/kustomize#5566) where Kustomize would ungracefully set the namespace of resources rendered by Helm, without consideration to .Release.Namespace in the templates. This was fixed as of kubernetes-sigs/kustomize#5940 and released with 5.8.1, but that has the significant (albeit intentional) side-effect of not setting .metadata.namespace unless the Helm chart does so explicitly. This breaks things for me and others that manage this Helm chart via Kustomize.

As far as I can tell, this PR would fix that issue and be fully backwards and forwards compatible between different versions of Kustomize.

[lindhe]

I don't have the authority to merge anything, but here's a review anyway to hopefully push things in the right direction. I think it'd be great if this could be merged soon.

[lindhe]

I don't think this matters a lot, since overly long input is uncommon, but if we want to truncate the namespace I guess we might as well do that for .Release.Namespace too. I'm not sure I like my own suggestion here (I think your stanza is sufficient), but here's a suggestion of what that could look like:

Suggested change

	{{- if .Values.namespaceOverride -}}
	{{- .Values.namespaceOverride | trunc 63 | trimSuffix "-" -}}
	{{- else -}}
	{{- .Release.Namespace -}}
	{{- end -}}
	{{- default .Release.Namespace .Values.namespaceOverride | trunc 63 | trimSuffix "-" -}}