Add namespace to kustomizations

[alzabo]

Hi there. I had trouble using these variants without adding these bits.

Without this change, these kustomiations fail to apply their patches
with errors like:

Error: no matches for OriginalId apps_v1_StatefulSet|~X|kafka; no
matches for CurrentId apps_v1_StatefulSet|~X|kafka; failed to find
unique target for patch apps_v1_StatefulSet|kafka

[solsson]

Does -n kafka apply -k work before the patch? The PR makes sense but I'm trying to figure out if something changed.

[bruwozniak]

For me kubectl apply -k works even without specifying namespace, but without this change, kustomize build fails, and that's what I prefer to use instead of applying to cluster directly.

[solsson]

without this change, kustomize build fails, and that's what I prefer to use instead of applying to cluster directly

Good point we should support GitOps flows. However then I can't reproduce the issue, with kustomize 2.0.3 which we stick with because it's the version built in to kubectl. What's your version of Kustomize? Maybe this is a change in Kustomize's behavior after all.

[solsson]

What happens if you use a kustomize base that sets a namespace: at the top level? I'd prefer if this repo could use Kustomize to phase out the hard coded namespace. We'd like to run many Kafka clusters in the same kubernetes cluster.

[alzabo]

I'm using kustomize 3.5.3 locally. Sorry, I see now that it wasn't clear that I was using the standalone kustomize vs. the version bundled with kubectl.

If I create a new Kustomization, when using this patch, the namespace set in the Kustomization is applied:

$ cat kustomization.yml
namespace: foobar
resources:
- variants/scale-1-ephemeral

$ kustomize build . | head
apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
  labels:
    origin: github.com_Yolean_kubernetes-kafka
  name: pod-labler
  namespace: foobar
rules:
- apiGroups:
  - ""

When working on my fork, where the HEAD has the patch from this PR, if I check out to the previous commit to remove the patch, kustomize build fails:

$ git checkout HEAD^
...
HEAD is now at 171d8f9 Merge pull request #301 from SteveKMin/patch-1

$ kustomize build .
Error: accumulating resources: recursed accumulation of path '/Users/my-user/kubernetes-kafka/variants/scale-1-ephemeral': accumulating resources: recursed accumulation of path '/Users/my-user/kubernetes-kafka/variants/scale-1': no matches for OriginalId apps_v1_StatefulSet|~X|kafka; no matches for CurrentId apps_v1_StatefulSet|~X|kafka; failed to find unique target for patch apps_v1_StatefulSet|kafka

[solsson]

Got it. The namespace in this PR identifies what to patch. With this diff the output from Kustomize 2.0.3 and 3.5.4 is equivalent, with or without a custom namespace name.