Kubernetes Strategic Merge Patch

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External

Internal

Overview

A strategic merge patch is a customized version of JSON patch and it looks like an incomplete YAML specification of a Kubernetes resource.

The SMP includes TypeMeta fields to establish the group/version/kind/name of the resource to patch, then just enough remaining fields to step into a nested structure to specify a new field value, e.g. an image tag. By default, an SMP replaces values. This is usually the desired behavior when the target value is a simple string, but may not be desired when the target value is a list. To change this default behavior, add a directive. Recognized directives in YAML patches are:

  • replace (the default)
  • delete

Also see:

JSON Patch
JSON Merge Patch

Example

The following patch updates the amount of memory allocated to a container in a pod and changes it to 1024Mi

apiVersion: v1
kind: Pod
metadata:
  name: my-pod
spec:
 containers:
 - name: my-container
   resources:
     limits:
       memory: 1024Mi