What is Kubernetes Container Resource Resize?

Question

Accepted Answer

**In-Place Resource Resize** — change container resources without restart.

```yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: myapp
spec:
  template:
    spec:
      containers:
      - name: app
        image: myapp:latest
        resources:
          requests:
            cpu: "250m"
            memory: "256Mi"
          limits:
            cpu: "500m"
            memory: "512Mi"
```

```bash
# Resize without restart (K8s 1.27+)
kubectl get pod my-pod -o yaml | \
  yq '.spec.containers[0].resources.requests.cpu = "500m"' | \
  yq '.spec.containers[0].resources.limits.cpu = "1000m"' | \
  kubectl apply -f -

# Or patch directly
kubectl patch pod my-pod --type=merge -p \
  '{"spec":{"containers":[{"name":"app","resources":{"requests":{"cpu":"500m","memory":"512Mi"},"limits":{"cpu":"1000m","memory":"1Gi"}}}]}}'

# Check resize status
kubectl get pod my-pod -o yaml | grep -A 5 resize

# Rollback to original
kubectl rollout undo deployment/myapp
```

**Requirements:**
- Kubernetes 1.27+ (beta).
- InPlacePodVerticalScaling feature gate enabled.
- Container must support resize (application-level).

**Behavior:**
- CPU can be resized in-place.
- Memory resize requires restart (not in-place).
- Pod status shows resize conditions.

DevOps: What is Kubernetes Container Resource Resize?