add bash-completion for comma separated list on kubectl get

[phil9909]

What type of PR is this?
/kind feature

What this PR does / why we need it:

kubectl get supports specifying a comma separated list of resource types. E.g.:

kubectl get pods,secrets

Will list all pods and secrets in the current namespace.

This commit adds support to the kubectl bash completion for this feature.
Which means if you type kubectl get pods,sec + tab it will be auto-completed to kubectl get pods,secrets (assuming the cluster does not have a CRD starting with sec).

Which issue(s) this PR fixes:

None

Special notes for your reviewer:

After running make kubectl you need to run source <(./_output/bin/kubectl completion bash) then you can try the new completion.

In theory other kubectl commands support comma separated lists of resources. One can do kubectl edit secret,configmap test which will open an editor with both resources (or fail if one or both don't exist).
As I think the use-cases for other commands are limited, I don't think we need completion for this.
Should this be proven wrong one can simply change the case block.

Does this PR introduce a user-facing change?:

kubectl: add support for bash-completion for comma separated list on `kubectl get`

Additional documentation e.g., KEPs (Kubernetes Enhancement Proposals), usage docs, etc.:

[k8s-ci-robot]

Hi @phil9909. Thanks for your PR.

I'm waiting for a kubernetes member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

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Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[phil9909]

/sig cli

[dougsland]

/assign

[dougsland]

/ok-to-test

[dougsland]

In general looks good the patch also tested. I have few comments.

./_output/local/go/bin/kubectl completion bash > ~/.kube/completion.bash.inc
./_output/local/go/bin/kubectl get pods,sec<TAB>

[dougsland]

/triage accepted
/priority backlog

[dougsland]

@phil9909 could you please squash the patches?

[phil9909]

could you please squash the patches?

Done. While I was on it, I also rebased onto master.

[dougsland]

/test pull-kubernetes-node-e2e

[dougsland]

Looks sane to me. We need one more people to review/approve.
/lgtm

[phil9909]

We need one more people to review/approve.

@brianpursley would you mind having a look?

[soltysh]

/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: phil9909, soltysh

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• staging/src/k8s.io/kubectl/OWNERS [soltysh]

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[phil9909]

/test pull-kubernetes-e2e-kind

[marckhouzam]

This is a nice change! Note that it does not seem to work for zsh.

But I have included this feature in the conversion from bash to Go code of #96087 which allows us to no longer worry about such differences.