Kubernetes Interview Guide

🟢 Easy (Basics)

1. What is Kubernetes?

An open‑source orchestrator for deploying, scaling, managing containers.

2. Pod?

Smallest unit; one/more containers sharing net & storage.

3. Deployment?

Manages ReplicaSets for rolling updates & rollback.

4. Service types?

ClusterIP, NodePort, LoadBalancer, ExternalName.

5. ConfigMap vs Secret?

ConfigMap = non‑sensitive; Secret = sensitive (encrypt at rest).

6. Probes?

liveness/readiness/startup to control restarts & traffic.

7. Namespace?

Logical isolation with quotas & RBAC scopes.

8. HPA/VPA/Cluster Autoscaler?

Pods scale (HPA), resources tune (VPA), nodes scale (CA).

🟡 Medium (Hands‑on)

1. StatefulSet vs Deployment?

Stable IDs/volumes vs stateless interchangeable pods.

2. NetworkPolicy?

Restrict pod traffic by selectors; needs CNI support.

3. StorageClass/PV/PVC?

Dynamic provision; claim volumes decoupled from pods.

4. Ingress?

L7 routing to Services via controller.

5. RBAC?

Roles/Bindings attach permissions to users/serviceaccounts.

6. Troubleshooting?

Describe/Logs/Exec; check Events, probes, limits, nodes.

🔴 Hard (Advanced)

1. etcd care?

TLS/auth, snapshots, HA cluster, DR rehearsals.

2. Multi‑cluster?

GitOps per cluster; mesh for traffic shaping.

3. Progressive delivery?

Canary/Blue‑Green via Argo Rollouts/Service Mesh.

4. Security hardening?

PSA restricted, drop caps, runAsNonRoot, NetworkPolicies.

🧪 Scenario Questions & Answers

1. Rollback quickly.

kubectl rollout undo to previous RS; pin images by digest.

2. CrashLoopBackOff.

Inspect logs/events; fix config, env, limits, readiness.

3. Inter‑ns isolation.

Default‑deny NetworkPolicies + targeted allows.

4. DB maintenance with SLO.

Use PDBs, read replicas, planned failover.

Generated for quick interview revision — basics, hands-on, advanced, and scenarios.