[1.26] kubelet: devices: skip allocation for running pods #118635

[ffromani]

What type of PR is this?

/kind bug
/kind regression

What this PR does / why we need it:

Cherry-pick of #118635 to branch release-1.26 through #119432. Cherry pick per se done using hack/cherry_pick_pull.sh

Original description

When kubelet initializes, runs admission for pods and possibly allocate requested resources. We need to distinguish between node reboot (no containers running) versus kubelet restart (containers potentially running).

Running pods should always survive kubelet restart. This means that device allocation on admission should not be attempted, because if a container requires devices and is still running when kubelet is restarting, that container already has devices allocated and working.

Thus, we need to properly detect this scenario in the allocation step and handle it explicitely. We need to inform the devicemanager about which pods are already running.

Which issue(s) this PR fixes:

Fixes #118559

Special notes for your reviewer:

Implements the first approach proposed in the thread, so we make the devicemanager treat running pod differently.

This approach was chosen because it seems simpler to make self-contained and easier to backport.

The devicemanager already tracks (with the help of the checkpoint files) which containers got devices assigned to them, which by definition means these containers passed its admission. The missing bit is safely learning which container are already running when initializing, and for that we extend the existing buildContainerMapFromRuntime

Does this PR introduce a user-facing change?

Fixes regression in 1.26.5 causing running pods with devices to be terminated if kubelet is restarted

[ffromani]

/sig node

[ffromani]

/retest

seems unrelated

[ffromani]

/test pull-kubernetes-e2e-gce-serial
/test pull-kubernetes-node-e2e-containerd

[swatisehgal]

/triage accepted
/priority important-soon

[ffromani]

rebased to fix a conflict

[ffromani]

/test pull-kubernetes-e2e-capz-windows-containerd-1-26

[swatisehgal]

/lgtm

Re-applying as the label was removed due to rebase

[k8s-ci-robot]

LGTM label has been added.

Git tree hash: d19eb9ab87ddee587ebee47c21c0756e51cf41ab

[bobbypage]

/lgtm

[bobbypage]

/cc @kubernetes/release-managers

Release managers, can you please take a look at this cherrypick? Thank you!

[ffromani]

/hold cancel

1.27 woes solved - and I think we won't merge cherry-picks out of expected order anyway

[xmudrii]

For RelEng:
/lgtm
/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: ffromani, mrunalp, xmudrii

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