What is a Kubernetes Service?

Question

Accepted Answer

**Service** — stable network endpoint for a set of Pods.

```yaml
# ClusterIP (default) — internal only
apiVersion: v1
kind: Service
metadata:
  name: user-service
spec:
  type: ClusterIP
  selector:
    app: user
  ports:
  - port: 80
    targetPort: 8080
---
# NodePort — exposed on node IP
apiVersion: v1
kind: Service
metadata:
  name: user-nodeport
spec:
  type: NodePort
  selector:
    app: user
  ports:
  - port: 80
    targetPort: 8080
    nodePort: 30080
---
# LoadBalancer — external cloud LB
apiVersion: v1
kind: Service
metadata:
  name: user-lb
spec:
  type: LoadBalancer
  selector:
    app: user
  ports:
  - port: 80
    targetPort: 8080
```

**Types:**
- ClusterIP: internal only.
- NodePort: exposed on node IP + port.
- LoadBalancer: external cloud LB.
- ExternalName: CNAME alias.

DevOps: What is a Kubernetes Service?