kustomize-basics

Kustomize manages Kubernetes configs across environments using a base-and-overlay structure. Create a base directory with your core deployment, then define overlays for each environment (development, production) that apply patches and transformations. Use kubectl -k overlays/production to deploy environment-specific configurations without duplicating manifests.

Overlays are directory structures that extend a base configuration for specific environments. Patches are modifications applied within overlays—JSON6902 patches for precise field changes and strategic merge patches for flexible updates. Together they let you customize replicas, images, labels, namespaces, and resource limits per environment.

Yes. Kustomize includes transformers for image tagging that update image references automatically and ConfigMapGenerator to create ConfigMaps directly from files or literals. SecretGenerator similarly handles secret creation, all declaratively within your kustomization.yaml file.

No. Kustomize eliminates the need for template syntax by using overlays, patches, and declarative transformers. You work with plain YAML and structured patch operations, making configuration management more readable and maintainable than template-based approaches.

Use the commonLabels and namePrefix transformers in your kustomization.yaml. These transformers automatically inject labels and prepend names to all resources in that overlay, ensuring consistent naming and labeling across multi-environment deployments.