Pod Management & Scheduling Flashcards

Which field in a Pod spec defines the list of init containers that run before app containers start?

Answer: initContainers

The `initContainers` field in the Pod spec lists containers that run to completion sequentially before any app containers start.

A Pod is in 'Pending' state for a long time. Which kubectl command best helps diagnose why it hasn't been scheduled?

Answer: kubectl describe pod

`kubectl describe pod` shows Events section with scheduler messages explaining why a pod cannot be placed.

What is the purpose of a PodDisruptionBudget (PDB)?

Answer: Limit voluntary disruptions by ensuring a minimum number of pods remain available

A PDB guarantees that a minimum number (or percentage) of pods stay available during voluntary disruptions like node drains.

Which scheduling feature allows you to spread pods evenly across failure domains like zones?

Answer: Topology Spread Constraints

Topology Spread Constraints use `topologyKey` to balance pod distribution across zones, nodes, or other topology domains.

In a multi-container Pod, how do containers share the network namespace by default?

Answer: All containers in a Pod share the same network namespace and IP

All containers within a Pod share one network namespace, meaning they share the same IP and can reach each other via localhost.

Which Pod restart policy causes a container to restart only if it exits with a non-zero exit code?

Answer: OnFailure

`restartPolicy: OnFailure` restarts the container only on non-zero exit codes, not on successful exits.

What does setting `terminationGracePeriodSeconds: 0` on a Pod do?

Answer: Forces immediate SIGKILL without waiting for graceful shutdown

Setting `terminationGracePeriodSeconds` to 0 bypasses the graceful shutdown window and sends SIGKILL immediately.