agent: Fix race condition with cgroup watchers #317
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In the CI, test containers intermittently fail to start after creation, with an error like below (see kata-containers#10872 for more details): # State: Terminated # Reason: StartError # Message: failed to start containerd task "afd43e77fae0815afbc7205eac78f94859e247968a6a4e8bcbb987690fcf10a6": No such file or directory (os error 2) I've observed this error to repro with the following containers, which have in common that they're all *very short-lived* by design (more tests might be affected): * k8s-job.bats * k8s-seccomp.bats * k8s-hostname.bats * k8s-policy-job.bats * k8s-policy-logs.bats Furthermore, appending a `; sleep 1` to the command line for those containers seemed to consistently get rid of the error. Investigating further, I've uncovered a race between the end of the container process and the setting up of the cgroup watchers (to report OOMs). If the process terminates first, the agent will try to watch cgroup paths that don't exist anymore, and it will fail to start the container. The added error context in notifier.rs confirms that the error comes from the missing cgroup: https://github.com/kata-containers/kata-containers/actions/runs/13450787436/job/37585901466#step:17:6536 The fix simply consists in creating the watchers *before* we start the container but still *after* we create it -- this is non-blocking, and IIUC the cgroup is guaranteed to already be present then. Fixes: kata-containers#10872 Signed-off-by: Aurélien Bombo <[email protected]>
Doesn't seem like we're going to use this and it's confusing when inspecting code. Signed-off-by: Aurélien Bombo <[email protected]>
Specify a GH API token to avoid the below throttling error: https://github.com/kata-containers/kata-containers/actions/runs/13450787436/job/37585810679?pr=10911#step:4:96 Signed-off-by: Aurélien Bombo <[email protected]>
danmihai1
approved these changes
Feb 25, 2025
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Merge Checklist
upstream/missinglabel (orupstream/not-needed) has been set on the PR.Summary
Backporting kata-containers#10911
Test Methodology