KubernetesPodOperator new callbacks and allow multiple callbacks

[johnhoran]

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I would like to have multiple callbacks in the kubernetes pod operator, and add two new callbacks. on_manifest_finalization would allow the callback to make changes just before the manifest is turned into a pod.
on_pod_wrapup would happen after the calls to on_pod_completion but just before the pod is deleted.

Adding both of these plus allowing multiple callbacks would allow you to do things in the kubernetes pod operator akin to how it approaches XComs but in a modular way. My use case here is I'm running DBT in kpo, and I want to do multiple things to the DBT artefacts after the DBT job has run, I could use on_manifest_finalization to insert an alpine sidecar with volumes mounted with the same intention as the XCom sidecar, where the sidecar keeps the volumes alive as files are extracted from it. on_pod_wrapup would allow me to insert a single sidecar and have multiple callbacks run their on_pod_completion before on_pod_wrapup kills the sidecar.

[amoghrajesh]

Good start!
Can you add few test cases that test more scenarios of more than 1 callback?

1. Few sync callbacks
2. Few async
3. Combination of both - trying to assert for order

[potiuk]

Some static checks to solve after rebase

[potiuk]

Note: We are in the process of moving all providers to a new structure - as part of #46045 so if you would like to avoid having to resolve conflicts, speedy fix and rebase is something that you might want to do @johnhoran

[potiuk]

See also devlist announcement: https://lists.apache.org/thread/dzbj5yx5kwpbwyr5yscp4wnlsp6p9v8l

[eladkal]

I fixed the static checks but the PR has conflicts @johnhoran can you please revase and resolve them?

[eladkal]

Failures are on papermill provider, not related to this PR

[boring-cyborg]

Awesome work, congrats on your first merged pull request! You are invited to check our Issue Tracker for additional contributions.

[potiuk]

Failures are on papermill provider, not related to this PR

Yep. already fixed in main