kustomize

Kustomize automates Kubernetes configuration management using bases and overlays to customize manifests declaratively. Organize your base resources in a directory with kustomization.yaml, then create environment-specific overlays that patch or merge configurations for dev, staging, and production without template syntax.

Yes, kustomize applies strategic merge and JSON Patch strategies to modify Kubernetes resources without templating. Patches let you fine-grained update specific fields—image versions, replicas, environment variables—while keeping your base manifests clean and reusable.

Kustomize includes generators to automatically create ConfigMaps and Secrets from files or literals, and image replacement transformers to update container images across resources. Define generators in kustomization.yaml to produce environment-specific configurations during the build step.

Kustomize uses declarative overlays, patches, and components instead of template logic, reducing complexity and improving readability. It composes final manifests by merging structured patches rather than rendering templates, making configurations easier to review and audit.

Yes, kustomize integrates directly with kubectl via the -k flag. Run kubectl apply -k overlays/dev to build and apply environment-specific configurations in a single command, or use kubectl kustomize to preview the final manifest before applying.

Yes, kustomize's base/overlay structure is designed for multi-environment deployments. Create a shared base with common resources, then define overlays for each environment that patch or add environment-specific settings, enabling a single source of truth across deployment stages.