Different Types of Patches

In this guide, we explore two methods to define patches within your kustomization configuration. By using either JSON 6902 patches or strategic merge patches, you can choose to embed your patches inline in your kustomization.yaml file or reference an external file that contains the patch definitions.

Inline Patching

The inline method involves embedding the patch directly into the kustomization.yaml file. This approach is ideal when you have a small number of patches, keeping your configuration straightforward. For instance, an inline patch to modify the replica count for a Deployment might look like this:

# Kustomization (inline method)
patches:
  - target:
      kind: Deployment
      name: api-deployment
    patch: |-
      - op: replace
        path: /spec/replicas
        value: 5

Separate File Patching

If your kustomization.yaml file becomes overly cluttered with many patch definitions, consider storing your patches in a separate file. This approach enhances maintainability and keeps your main configuration file clean. In your primary kustomization.yaml file, reference the external patch file as shown below:

# Kustomization (separate file reference)
patches:
  - path: replica-patch.yaml
    target:
      kind: Deployment
      name: nginx-deployment

Within the external file (replica-patch.yaml), you can list all the necessary modifications for your deployment. This method is especially useful for larger projects where organizing patches into dedicated files improves clarity.

Strategic Merge Patch Example

Strategic merge patches are an alternative to JSON 6902 patches and can also be defined inline or referenced via an external file. Below are examples demonstrating both methods.

Inline Strategic Merge Patch

# Inline strategic merge patch
patches: |
  - patch: |-
      apiVersion: apps/v1
      kind: Deployment
      metadata:
        name: api-deployment
      spec:
        replicas: 5

Separate File Reference for Strategic Merge Patch

# Separate file reference for strategic merge patch
patches:
  - replica-patch.yaml

By selecting the most appropriate method for your needs—whether inline or separate file patching—you can maintain a clean and organized configuration. This not only ensures clarity in managing JSON 6902 patches and strategic merge patches but also improves overall project maintainability.

For more insights on managing kustomizations and patches, explore the Kustomize documentation.