feat(ws): add podTemplatePod to Workspace status, for backend logs

[thesuperzapper]

related: #208
related: #172

Currently, it would have been impossible for the backend to know which pod to read logs from as part of #208, so this PR adds podTemplatePod to the status of Workspaces.

This new status field will look something like (when the Pod exists):

status:
  podTemplatePod:
    name: ws-jupyterlab-workspace-56mlf-0
    containers:
      - name: main
    initContainers: []

This new status field will look something like (when the Pod does not exist):

status:
  podTemplatePod:
    name: ""

---

This PR also:

• improves the generateWorkspaceStatus method by factoring out a generateWorkspaceState to generate the state/stateMessage
• ensures we only do an UPDATE call when the status actually changes on WS and WSK (reduce API load)
• factors out a common workspacePodTemplateContainerName variable, rather than using "main" everywhere

[thesuperzapper]

@ederign this should be ready to review/lgtm

[ederign]

I'm learning how controller works, so just left a few comments to clarify. @etirelli @harshad16 @andyatmiami maybe one of you can take a look on it?

[ederign]

@thesuperzapper, just to double-check that this was intentional!

[ederign]

Do we need to also change https://github.com/kubeflow/notebooks/blob/notebooks-v2/workspaces/controller/test/e2e/e2e_test.go#L38 ?

[thesuperzapper]

It was just an automated thing, but it was a mistake, yes!

It happens if you run make docker-build without IMG set.

[thesuperzapper]

Fixed in 689c828

[ederign]

I'm new for controller, but why we don't need workspace.Status.PendingRestart = false anymore?

[thesuperzapper]

@ederign a few lines up I realized we were not always correctly setting it.

Now I build the status by setting it to false at the beginning and then only setting it to true when I detect an option has a redirect.

[ederign]

Thank you for the clarification!

[thesuperzapper]

@ederign this should be good to LGTM now, I removed the accidental image diff in 689c828

[ederign]

/lgtm

[harshad16]

still getting upto speed with codeblock
lgtm in general

just one question

[harshad16]

Is there initcontainerstatus maintained some other place ?

[thesuperzapper]

@harshad16 you are correct that the initContainer status is stored under status.InitContainerStatuses, but in this case, we are looking for the status of the "main" container, so we can get info about it.

But you are correct that we might have a problem if the Pod is failing because an init-container (or in fact some other container is in an error state), as we would fall through to the Unknown State.

Do you want to pick this up as another task after we merge?

[thesuperzapper]

I am merging this for now, but as @harshad16 said in #210 (comment), there is still some work to do on the state extraction.

/approve

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[thesuperzapper]

Hmm, it seems like we now always need to have the ok-to-test label because otherwise the job is marked as "skipped" which seems to be failure.

/ok-to-test