Kustomize

Kustomize at a glance

Kustomize is a widely used tool for customizing Kubernetes manifests without templates, built into kubectl and used across many GitOps workflows. Kustomize ships regular releases plus fixes; as tooling that produces the manifests applied to clusters, keeping it and your bases current matters.

For admins Kustomize's version comes both standalone and bundled in kubectl — be aware which you use, and keep it compatible with your Kubernetes version. The bigger version story is the bases and images your overlays reference: those carry the actual security posture, so track upstream and update deliberately. Kustomize can generate secrets — keep the source material out of version control in plain form. After upgrading Kustomize or bumping a base, render (build) and review the diff before applying, since subtle behaviour changes across versions can alter output. Pin versions for reproducibility. Patchletter surfaces new Kustomize releases.