patchesJson6902

PatchesJson6902 is a mechanism used by Kustomize to apply JSON Patch operations (RFC 6902) to selected Kubernetes resources during customization. It enables precise modifications of individual fields and is an alternative to patchesStrategicMerge when fine-grained changes are required. It is processed during the build of a kustomization and results in a patched set of resources.

Structure: In a kustomization.yaml, patchesJson6902 is a list. Each item defines targets and a patch. The targets block identifies the intended resources by group, version, kind, name, and optional namespace. The patch is a YAML block that encodes a JSON Patch array, with operations such as op, path, and value. Paths follow JSON Pointer syntax relative to the resource JSON.

Example:

patchesJson6902:

- targets:

group: apps

version: v1

kind: Deployment

name: nginx-deployment

namespace: default

patch: |-

- op: replace

path: /spec/replicas

value: 3

Behavior and considerations: JSON Patch operations can add, replace, remove, move, copy, or test values. It can patch multiple resources by providing multiple entries. It is supported by Kustomize builds; compatibility with older tooling should be verified. Correct usage depends on accurate target selectors and valid JSON Pointer paths; errors in paths or mismatched resource structures can cause patch failures. It is particularly useful for small, nested changes where a full merge is unnecessary.

See also: The mechanism is based on RFC 6902 and is part of Kustomize’s patching capabilities for Kubernetes manifests.