Pod Management & Scheduling Flashcards

Which field enables a Pod to run as a specific user ID at the container level?

Answer: securityContext.runAsUser

Setting `securityContext.runAsUser` in a container spec makes the container process run as the specified UID.

What is the role of the `scheduler.alpha.kubernetes.io/node` annotation on a Pod?

Answer: It manually assigns the pod to a specific node, bypassing the scheduler

Setting `nodeName` (or the legacy node annotation) bypasses the scheduler entirely and directly binds the pod to the named node.

A readiness probe failing on a pod causes which behavior?

Answer: The pod's IP is removed from the Service's Endpoints, stopping traffic

A failing readiness probe removes the pod from Service endpoints so no traffic is routed to it, without killing the container.

Which Kubernetes concept allows a pod to request exclusive access to a GPU or custom device on a node?

Answer: Device Plugins and resource limits with extended resources

Device Plugins expose custom resources (like `nvidia.com/gpu`) that pods can request via `resources.limits` in their container spec.

What happens to pods managed by a ReplicaSet when you manually delete one of them?

Answer: The ReplicaSet controller creates a replacement pod to maintain the desired replica count

The ReplicaSet controller continuously reconciles actual vs desired state and immediately creates a new pod to replace the deleted one.

Which field in a Pod spec prevents a pod from being scheduled on a node that already runs a pod with a matching label?

Answer: affinity.podAntiAffinity

`podAntiAffinity` rules repel a pod from nodes that already host pods matching the specified label selector.

In Kubernetes, what is a 'sidecar container' pattern?

Answer: An auxiliary container in the same Pod that extends or supports the main application container

A sidecar is a co-located container in the same pod that provides supporting functionality like logging, proxying, or config sync alongside the main app.