K
Q

Patch specific resource in kustomize

2/19/2021

I have a base resource that gets imported in an overlay, which in the overlays also makes other resources from the same base but with a different suffix. In the overlay, the base resource needs to be patched without affecting the other newly created resources. However, all three of them are changed. How can I just modify the one I am intending to modify?

Below is an example of this. The base resource is a Deployment with 1 replica. In the overlay, the base is added as a resource but I try to patch it and set the replicas to 0. Unfortunately, all replicas of all deployments get set to 0.

Base

EX_HOME=$(mktemp -d)
BASE=$EX_HOME/base
mkdir $BASE

cat <<EOF >$BASE/deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: example
  labels:
    app: example
spec:
  replicas: 1
  selector:
    matchLabels:
      app: example
  template:
    metadata:
      labels:
        app: example
    spec:
      containers:
        - name: example
          image: alpine:latest
          command: ["sh","-c", "sleep 1h"]
EOF

cat <<EOF>$BASE/kustomization.yaml
resources:
- deployment.yaml
EOF

Overlay

OVERLAYS=$EX_HOME/overlays
mkdir -p $OVERLAYS/srv0
mkdir -p $OVERLAYS/srv1

cat <<EOF>$OVERLAYS/kustomization.yaml
resources:
  - svr0
  - svr1
  - ../base

patches:
  - patch: |-
      - op: replace
        path: /spec/replicas
        value: 0
    target:
      kind: Deployment
      group: apps
      version: v1
      name: example
EOF

cat <<EOF>$OVERLAYS/svr0/kustomization.yaml
resources:
  - ../../base
nameSuffix: -svr0
EOF

cat <<EOF>$OVERLAYS/svr0/kustomize.yaml
resources:
  - ../../base
nameSuffix: -svr1
EOF
-- H. S&#225;nchez
kubernetes
kustomize

Similar Questions

Using ray with Jupyterhub on Kubernets cluster
Running Grafana (in k3s) behind (zuul) reverse proxy with sub path
Grafana throw error after selecting more than 60 variables
Kubernetes Helm Redis Google Cloud MemoryStore - Service vs Endpoint
Create per-file Kubernetes secrets from a directory of text files in Kustomize

1 Answer

2/25/2021

The following should work. I took the liberty to re-organize a bit the directory structure to make it clearer. Since you only update the replica count I also switched to the replicas transformer instead of a patch:

base/kustomization.yaml:

resources:
  - deployment.yaml

overlays/svr0/kustomization.yaml:

resources:
  - ../../base

nameSuffix: -svr0

overlays/svr1/kustomization.yaml:

resources:
  - ../../base

nameSuffix: -svr1

`overlays/all/kustomization.yaml`:
```yaml
resources:
  - ../../base
  - ../svr0
  - ../svr1

replicas:
  - name: example-svr0
    count: 0
  - name: example-svr1
    count: 0

On a side note: There is two ways to go about it. Here I add the replicas transformer at the top. You could also add it once in overlays/svr0/kustomization.yaml and once in verlays/svr1/kustomization.yaml instead. If you do so the transformer will become:

replicas:
  - name: example
    count: 0
-- ITChap
Source: StackOverflow