Kustomize

Kustomize is the Kubernetes manifest customization CLI built around kustomization.yaml files. It composes bases, overlays, patches, generators, and optional functions into rendered YAML without templating.

• Render environment-specific Kubernetes manifests from shared bases, overlays, patches, labels, namespaces, images, and generators.
• Create or edit kustomization.yaml files from the shell, including adding resources, setting images or replicas, and fixing older config syntax.
• Vendor remote configuration into a local directory with localize, then hand the rendered YAML to kubectl, CI, or review steps.

• kustomize build is deterministic and non-interactive, so agents can inspect generated YAML, diff outputs, and pipe results into follow-up commands.
• The tool works mainly on files rather than live cluster state, which keeps edits auditable but usually means pairing it with kubectl for apply and verification.
• Structured output is limited: core workflows are YAML-first, while JSON is only available on ancillary commands such as version -o json and hidden openapi fetch --format json.

• localize is marked alpha, and its source notes that Helm and KRM plugin fields are not yet localized.
• Plugin, Helm, and function-based flows can require extra flags, external binaries, or container execution, which raises the complexity of unattended runs.