Kustomize

Kustomize manages declarative configuration of Kubernetes resources. It allows users to customize YAML manifests through overlays, enabling reuse across different environments without needing templating languages. The tool operates natively with Kubernetes YAML, providing features like applying patches, setting images, and managing common labels and annotations.

The package includes both a standalone binary program and a Go library. The binary offers commands for building kustomizations, editing files, and generating completions. The library provides programmatic access for developers to integrate customization into applications and workflows, supporting resource composition, patching, and variable substitution.

Kustomize is ideal for teams managing complex Kubernetes deployments, ensuring consistent configurations across development, staging, and production environments.

Kustomize processes kustomization files (kustomization.yaml) that define bases, patches, and generators. It builds complete YAML configurations by composing resources from directories or URLs, applying strategic merge patches, and substituting variables. The tool uses a declarative approach, merging resources via 2-way or 3-way strategies, and supports alpha features like configuration functions and localization.