Kustomize: Patch multiple resources that starts with same name

Question

I want to patch multiple deployments that starts with same namePrefix instead of targeting specific resource.

For example, I have 2 deployments of nginx deployment-v1.yaml and deployment-v2.yaml. I want to patch both the deployment using nginx- prefix.

deployment-v1.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-v1
  labels:
    app: web
spec:
  selector:
    matchLabels:
      app: web
  replicas: 5
  strategy:
    type: RollingUpdate
  template:
    metadata:
      labels:
        app: web
    spec:
      containers:
       —name: nginx
          image: nginx
          ports:
           —containerPort: 80

deployment-v2.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
  labels:
    app: web
spec:
  selector:
    matchLabels:
      app: web
  replicas: 5
  strategy:
    type: RollingUpdate
  template:
    metadata:
      labels:
        app: web
    spec:
      containers:
       —name: nginx
          image: nginx
          resources:
            limits:
              memory: 200Mi
            requests:
              cpu: 100m
              memory: 200Mi
          ports:
           —containerPort: 80

Now I want to overlay both the deployments with common overlay-patch. I am trying something like this.

overlay.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  namePrefix: nginx-
spec:
  replicas: 10

kustomization.yml

apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
resources:
  - deployment-v1.yaml
  - deployment-v2.yaml
patchesStrategicMerge:
  - overlay.yaml

But it is not working as it is expecting a name to match the target and totally ignoring namePrefix. Any help is appreciated.

It helps if the examples you post in your question are syntactically valid. There are indentation problems with these manifests and the character `—` is not the same as `-`. These problems make these files invalid. — larsks, Jul 13 '23 at 12:28

larsks · Accepted Answer · 2023-07-13T12:51:39.073

You can apply a patch to multiple resources using the target attribute in a patch. Given your examples (after fixing the errors I pointed out in my comment), we can write a kustomization.yaml like this:

apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
resources:
- deployment-v1.yaml
- deployment-v2.yaml

patches:
  - target:
      kind: Deployment
    patch: |
      apiVersion: apps/v1
      kind: Deployment
      metadata:
        name: this_value_is_ignored
      spec:
        replicas: 10

The target attribute controls to what resources this patch will apply. With the above configuration, running kustomize build results in:

apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: web
  name: nginx-deployment
spec:
  replicas: 10
.
.
.

and:

apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: web
  name: nginx-v1
spec:
  replicas: 10
.
.
.

The above configuration would apply the patch to all deployments in your kustomization. If you wanted to limit the patching to only deployments matching a specific name prefix, you could write:

apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
resources:
- deployment-v1.yaml
- deployment-v2.yaml

patches:
  - target:
      kind: Deployment
      name: nginx.*
    patch: |
      apiVersion: apps/v1
      kind: Deployment
      metadata:
        name: this_value_is_ignored
      spec:
        replicas: 10

Note that the name pattern is regular expression, not a shell-style glob.

Thanks. It is working. However, I am not sure about the regular expression. It seems to be targeting all the Deployment manifests. — Pradyskumar, Jul 18 '23 at 07:42
The regex absolutely works as intended. [Here](https://github.com/larsks/so-example-76678256-patch-multiple) is a demo repository; run `kustomize build` and you'll see that the patch is only applied to the `web.*` deployments. — larsks, Jul 18 '23 at 13:26

Kustomize: Patch multiple resources that starts with same name

1 Answers1