k8snetworkplumbingwg / multus-cni / 30124900396

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Pull #1525

github

This PR introduces graceful shutdown functionality to the Multus daemon by adding a /readyz endpoint

That is added alongside the existing /healthz. The /readyz endpoint starts returning 500 once a SIGTERM is received, indicating the daemon is in shutdown mode. During this time, CNI requests can still be processed for a short window. The daemonset configs have been updated to increase terminationGracePeriodSeconds from 10 to 30 seconds, ensuring we have a bit more time for these clean shutdowns.

This addresses a race condition during pod transitions where the readiness check might return true, but a subsequent CNI request could fail if the daemon shuts down too quickly. By introducing the /readyz endpoint and delaying the shutdown, we can handle ongoing CNI requests more gracefully, reducing the risk of disruptions during critical transitions.

Major thanks to @deads2k for the find, identification, fix, and of course, the explanations. Appreciate it.

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