kustomize

Build kustomization from current directory

$ kustomize build .

$ kustomize build [path/to/overlay]

$ kustomize build [https://github.com/org/repo//path]

$ kustomize create

$ kustomize create --autodetect

$ kustomize edit add resource [deployment.yaml]

$ kustomize edit set namespace [my-namespace]

$ kustomize edit set image [nginx:1.25]

kustomize command [options]

kustomize customizes Kubernetes YAML configurations without templates. It uses a kustomization.yaml file to declaratively specify base resources and overlay modifications like patches, labels, namespaces, and image tags.
The tool follows a base/overlay pattern: bases contain common resources, overlays customize them for specific environments (dev, staging, prod). This approach avoids duplication while maintaining environment-specific differences.
Kustomize is built into kubectl (since v1.14) as kubectl kustomize and kubectl apply -k. The standalone CLI provides the latest features and is recommended for advanced use cases.
Key concepts include resources (YAML files to include), patches (strategic merge or JSON patches), configMapGenerator and secretGenerator (generate ConfigMaps/Secrets from files), and vars (variable substitution).

--enable-helm

Enable Helm chart inflator generator.

Enable alpha kustomize plugins.

Use uid and gid of command executor.

Control file loading: LoadRestrictionsRootOnly or LoadRestrictionsNone.

Write output to file instead of stdout.

Print stack trace on error.

Show help information.

build [path]

Build kustomization target from directory or URL to stdout.

Create a new kustomization.yaml in current directory.

Edit an existing kustomization.yaml file.

Commands for reading and writing configuration.

Commands for running functions against configuration.

Generate shell completion script.

Print kustomize version.

Help about any command.

edit add resource file

Add a resource to kustomization.

Add a patch file.

Set the namespace for all resources.

Set or override an image tag.

Set replica count for a deployment.

Add a label to all resources.

Add an annotation to all resources.

The kubectl-embedded version may lag behind the standalone CLI. Some features require --enable-helm or --enable-alpha-plugins flags. Variable substitution has limitations compared to templating tools like Helm.

Kustomize was developed by the Kubernetes SIG CLI team starting around 2017 as a template-free approach to Kubernetes configuration management. It was integrated into kubectl in version 1.14 (2019). The project emphasizes declarative configuration and follows Kubernetes' philosophy of desired state management.

kubectl(1), helm(1), k9s(1)