mediumkubernetes-docs#declarative-state#controllers#health-checks

Observe a Kubernetes Deployment Rollout

Deploy a small stateless workload, scale it, change its image, and inspect how desired and ready state differ over time.

The Runtime Theory TeamSeptember 25, 20261 min read

Solve it

Solving happens on the judge — come back and mark it done

Sample cases

inSet replicas from 1 to 3

outObserve the Deployment, ReplicaSet, Pods, scheduling, and readiness transition

inUse an invalid image tag in a test namespace

outIdentify image-pull failure from Pod conditions and events; restore a valid image

Use a local disposable cluster or an authorized learning environment. Create a Deployment, inspect its desired and ready replica counts, scale it, and change the pod template to trigger a rollout.

Watch the Deployment, ReplicaSet, Pods, and events during each transition. Introduce an invalid image tag only in this isolated exercise, diagnose the pull failure, then restore a working image. Explain why the API can accept a Deployment before its Pods are ready.

Finish by describing how a readiness probe differs from a liveness probe and what traffic behavior you expect while a new Pod starts. The linked Kubernetes tutorial provides the setup and basic operations.

One dispatch a week

The trace behind each problem, the tradeoff that explains it, and one technical dispatch per week — no noise.

One technical dispatch per week. No noise.

Not started