graceful shutdown

The question that separates people who have debugged a hung rollout from people who have read about one. The interesting half is not the signal, it is PID 1.

PDB governs voluntary disruptions only and does not gate rolling updates at all. Candidates who say 'it keeps N pods alive' have just described the part it does not do.

Pod-level SIGTERM handling and node-level shutdown coordination are different mechanisms, and conflating them is the trap. The kubelet can only drain pods on power-off if it participates in systemd's shutdown sequence.