What is Kubernetes Pod Lifecycle Phase?

Question

Accepted Answer

**Phase** — high-level Pod state.

```yaml
apiVersion: v1
kind: Pod
metadata:
  name: my-pod
spec:
  containers:
  - name: app
    image: nginx:latest
    resources:
      requests:
        cpu: "100m"
        memory: "128Mi"
      limits:
        cpu: "200m"
        memory: "256Mi"
    startupProbe:
      httpGet:
        path: /healthz
        port: 80
      failureThreshold: 30
      periodSeconds: 10
    readinessProbe:
      httpGet:
        path: /ready
        port: 80
      initialDelaySeconds: 5
      periodSeconds: 10
    livenessProbe:
      httpGet:
        path: /healthz
        port: 80
      initialDelaySeconds: 15
      periodSeconds: 20
```

```bash
# Check Pod phase
kubectl get pod my-pod -o jsonpath='{.status.phase}'

# View all Pod phases
kubectl get pods -o custom-columns=NAME:.metadata.name,PHASE:.status.phase,NODE:.spec.nodeName,RESTARTS:.status.containerStatuses[*].restartCount

# Check Pod conditions
kubectl get pod my-pod -o jsonpath='{.status.conditions[*].type}'
kubectl get pod my-pod -o jsonpath='{.status.conditions[*].status}'

# Watch phase changes
kubectl get pods -w
kubectl get events --field-selector involvedObject.name=my-pod

# Check pending Pods
kubectl get pods --field-selector status.phase=Pending
kubectl get pods --field-selector status.phase=Failed
kubectl get pods --field-selector status.phase=Succeeded
```

**Phases:**
- Pending: waiting for scheduling.
- Running: at least one container running.
- Succeeded: all containers terminated successfully.
- Failed: at least one container failed.
- Unknown: unable to get Pod status.

**Transitions:**
- Pending → Running → Succeeded/Failed.
- Failed → Running (on restart).
- Unknown → Running (on node recovery).

DevOps: What is Kubernetes Pod Lifecycle Phase?