What is Kubernetes kustomize?

Question

Accepted Answer

**Kustomize** — template-free way to customize Kubernetes manifests.

```yaml
# kustomization.yaml
apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
resources:
- deployment.yaml
- service.yaml
namePrefix: prod-
namespace: production
commonLabels:
  env: production
  team: platform
patches:
- target:
    kind: Deployment
    name: myapp
  patch: |
    - op: replace
      path: /spec/replicas
      value: 3
    - op: add
      path: /spec/template/spec/containers/0/resources/limits/memory
      value: "512Mi"
configMapGenerator:
- name: app-config
  literals:
  - LOG_LEVEL=info
secretGenerator:
- name: app-secrets
  literals:
  - DB_PASSWORD=secret123
```

```bash
# Preview output
kubectl kustomize .

# Apply
kubectl apply -k .
```

**vs Helm:**
- Kustomize: overlay-based, no templates.
- Helm: template-based, more powerful.

DevOps: What is Kubernetes kustomize?