Explain Kubernetes core concepts — Pods, Deployments, and Services

Question

"We're moving from Docker Compose to K8s. Explain the core resources."

Interview OS Community · Accepted Answer

## Hierarchy
Deployment → ReplicaSet → Pod(s) → Container(s), Service → routes to Pod(s)

## Deployment (manages Pods)
```yaml
apiVersion: apps/v1
kind: Deployment
spec:
  replicas: 3
  selector: { matchLabels: { app: interviewos } }
  template:
    spec:
      containers: [{ name: web, image: interviewos:latest, ports: [{ containerPort: 3000 }] }]
```

## Service (networking)
```yaml
kind: Service
spec:
  selector: { app: interviewos }
  type: LoadBalancer
  ports: [{ port: 80, targetPort: 3000 }]
```

| Resource | Purpose |
|----------|---------|
| Pod | Runs containers |
| Deployment | Manages replicas, updates, rollbacks |
| Service | Stable IP, load balancing |
| ConfigMap | Configuration |
| Secret | Sensitive data |

Interview OS

Explain Kubernetes core concepts — Pods, Deployments, and Services

Question Details

Suggested Solution

Hierarchy

Deployment (manages Pods)

Service (networking)

Discussion (0)

Resource	Purpose
Pod	Runs containers
Deployment	Manages replicas, updates, rollbacks
Service	Stable IP, load balancing
ConfigMap	Configuration
Secret	Sensitive data