Patches List

  • Example api-depl.yaml file: 
    apiVersion: apps/v1
kind: Deployment
metadata:
name: api-deployment
spec:
replicas: 1
selector:
  matchLabels:
    component: api
template:
  metadata:
    labels:
      component: api
  spec:
    containers:
      - name: nginx
        image: nginx

  • The containers section above expects a list, that’s why you see the - before name: nginx

  • This is using a Replace List with Json6902

  • kustomization.yaml: ``` patches:
    • target: kind: Deployment name: api-deployment patch: |-
      • op: replace path: /spec/template/spec/containers/0 value: name: haproxy image: haproxy ```

  • The path to a container

  • This is the first container, therefore it will have an index of 0.

  • Changes the containers name and image to haproxy.

  • How to replace a list using the Strategic Merge Path
kustomization.yaml

patches:
  - label-patch.yaml
  • The label-patch.yaml file looks like this: 
    apiVersion: apps/v1
kind: Deployment
metadata:
name: api-deployment
spec:
template:
  spec:
    containers:
      - name: nginx
        image: haproxy

  • How to add an item to a list using a Json6902 patch.

  • We have the same deployment configuration, this will be the nginx container.

  • We want to add a second container to this list: ``` containers:
    • name: nginx image: ngin ```
  • This is the kustomization.yaml file: ``` patches:
    • target: kind: Deployment name: api-deployment patch: |-
      • op: add path: /spec/template/spec/containers/- value: name: haproxy image: haproxy ```

  • The operation is set to add.

  • At the end of the path, we have a -. The dash means to add it at the end of the list. If we wanted to add the containers to the front of the list, this would be a zero.

  • The final configuration would look like this:
containers:
  - name: nginx
    image: ngin

  • Adding an item to a list using a Strategic Merge Patch:

  • kustomization.yaml: ``` patches:
    • label-patch.yaml ```
  • The label-patch.yaml:
apiVersion: apps/v1
kind: Deployment
metadata:
  name: api-deployment
spec:
  template:
    spec:
      containers:
        - name: haproxy
          image: haproxy

  • How to delete an item from a list using a Json6902 patch.

  • We have two containers and the one with the name of database needs to be deleted: ``` containers:
    • name: web image: nginx
    • name: database image: mongo ```
  • kustomization.yaml file: ``` patches:
    • target: kind: Deployment name: api-deployment patch: |-
      • op: remove path: /spec/template/spec/containers/1 ```

  • We want to remove the second one, so therefore we use an index of 1.

  • How to delete an item using a Strategic Merge Patch:

  • kustomization.yaml:
patches:
  - label-patch.yaml
  • label-patch.yaml:
apiVersion: apps/v1
kind: Deployment
metadata:
  name: api-deployment
spec:
  template:
    spec:
     containers:
       - $patch: delete
         name: database
  • The $patch directive is the delete directive which specifies the container to delete

Updated: