jupyter-web-app's PodDefault configurations are keyed by their label selector's key, not their name

[ca-scribner]

/kind bug

What steps did you take and what happened:
The Notebook spawner page is configured using the spawner_ui_config.yaml input file.
The configurations section lets an admin define which PodDefaults should be selected by default. spawner_ui_config.yaml's comments state:

the list of PodDefault names that are selected by default

If I create a PodDefault named example:

apiVersion: kubeflow.org/v1alpha1
kind: PodDefault
metadata:
 name: example
spec:
 desc: Example PodDefault
 env:
 - name: SOMETHING
   value: stuff
 selector:
   matchLabels:
     example-match-selector: "true"

then set the spawner_ui_config.yaml's configurations to:

  configurations:
    readOnly: false

    # the list of PodDefault names that are selected by default
    # (take care to ensure these PodDefaults exist in Profile Namespaces)
    value:
    - example

I do not see it selected in the spawner UI by default:

What did you expect to happen:

When specifying PodDefaults by name in the spawner_ui_config.yaml, I expect them to be selected by default on the spawner page:

Anything else you would like to add:

I think this is a bug in the jwa backend's get_poddefaults(). get_poddefaults() returns a result where the label field is set as the key of the 0th matchLabels selector:

kubeflow/components/crud-web-apps/jupyter/backend/apps/common/routes/get.py

Lines 29 to 49 in bd7f250

	@bp.route("/api/namespaces/<namespace>/poddefaults")
	def get_poddefaults(namespace):
	pod_defaults = api.list_poddefaults(namespace)
	# Return a list of pod defaults adding custom fields (label, desc) for
	# forms
	contents = []
	for pd in pod_defaults["items"]:
	label = list(pd["spec"]["selector"]["matchLabels"].keys())[0]
	if "desc" in pd["spec"]:
	desc = pd["spec"]["desc"]
	else:
	desc = pd["metadata"]["name"]
	pd["label"] = label
	pd["desc"] = desc
	contents.append(pd)
	log.info("Found poddefaults: %s", contents)
	return api.success_response("poddefaults", contents)

This can be confirmed by setting

  configurations:
    readOnly: false

    # the list of PodDefault names that are selected by default
    # (take care to ensure these PodDefaults exist in Profile Namespaces)
    value:
    - example-match-selector

And reloading/refreshing the spawner page:

I think this should probably instead be:

        label = pd["metadata"]["name"]  # haven't compiled this - might have typo'd something

Environment:

• Kubeflow version: (version number can be found at the bottom left corner of the Kubeflow dashboard): 1.8
• kfctl version: (use kfctl version):
• Kubernetes platform: (e.g. minikube)
• Kubernetes version: (use kubectl version):
• OS (e.g. from /etc/os-release):

[ca-scribner]

This bug is also the cause of #6812, which identified how a the jwa fails to handle PodDefaults that have no matchLabels selector

[ca-scribner]

This bug appears to also affect the tensorboard web app backend, which has a copy of the same get_poddefaults()

[ca-scribner]

I don't understand typescript enough to be certain that the label is intended to be the name of the PodDefault, but given the comments in the spawner_ui_config.yaml I think that's probably true

[boarder7395]

@ca-scribner I'm looking at the code in a little more detail and I see what you're saying. I think both our solutions are not optimal though.

This logic uses the matchLabel key to set a the label on the notebook to true.

kubeflow/components/crud-web-apps/jupyter/backend/apps/common/form.py

Lines 253 to 261 in bd7f250

	def set_notebook_configurations(notebook, body, defaults):
	notebook_labels = notebook["metadata"]["labels"]
	labels = get_form_value(body, defaults, "configurations")
	if not isinstance(labels, list):
	raise BadRequest("Labels for PodDefaults are not list: %s" % labels)
	for label in labels:
	notebook_labels[label] = "true"

For this reason I think we need to use the label of the poddefault instead of the name of the poddefault.

BUT I'm not sure this should be the actual logic. Lets take a look at the issue with my solution . Consider the pod default

metadata:
  name: example
spec:
  annotations:
    karpenter.sh/do-not-disrupt: "true"
  selector:
    matchExpressions:
    - key: some-key
      operator: NotIn
      values: ['true']

In this case the configuration should be "some-key" and selecting that configuration in the dropdown would add the "some-key" label to the notebook. Although due to the matchExpressions that is doing the exact opposite of what we want.

I'm currently at a wall with matchExpressions because what we really want to do use this selector to create a label that conforms to the matchExpressions requirement.

[boarder7395]

@thesuperzapper Do you have any input on the above