How to change container name and image in kustomization.yaml - kubernetes

Question

I want to change all the dev-app to demo-app using kustomization.
In my base deployment.yaml I have the following:
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
labels:
service: dev-app
name: dev-app
spec:
replicas: 1
selector:
matchLabels:
app: dev-app
template:
metadata:
labels:
service: dev-app
spec:
imagePullSecrets:
- name: my-docker-secret
containers:
- name: dev-app
image: the-my-app
imagePullPolicy: Always
ports:
- containerPort: 1234
restartPolicy: Always
In my overlays/demo kustomization.yaml I have the following:
bases:
- ../../base
resources:
- deployment.yaml
namespace: demo-app
images:
- name: the-my-app
newName: my.docker.registry.com/my-project/my-app
newTag: test
when I do this:
kubectl apply -k my-kustomization-dir
result look like this:
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
labels:
service: dev-app
name: dev-app
spec:
replicas: 1
selector:
matchLabels:
app: dev-app
template:
metadata:
labels:
service: dev-app
spec:
imagePullSecrets:
- name: my-docker-secret
containers:
- name: dev-app
image: my.docker.registry.com/my-project/my-app:test
imagePullPolicy: Always
ports:
- containerPort: 1234
restartPolicy: Always
I want to change the name in the container to demo-app.
containers:
- name: dev-app
if possible help me with best possible way to replace all the dev-app name,label,service tag to demo-app

Answer 1

A way to do this is to replicate your deployment file into your overlays folder and change what you need to change, for example:
Path structure:
├── base
│   ├── deployment.yaml
│   └── kustomization.yaml
└── overlays
├── dev
│   ├── deployment.yaml
│   └── kustomization.yaml
└── prod
├── deployment.yaml
└── kustomization.yaml
deployment file of base/ folder:
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
labels:
service: dev-app
name: dev-app
spec:
replicas: 1
selector:
matchLabels:
app: dev-app
template:
metadata:
labels:
service: dev-app
spec:
imagePullSecrets:
- name: my-docker-secret
containers:
- name: dev-app
image: the-my-app
imagePullPolicy: Always
ports:
- containerPort: 1234
resources:
limits:
cpu: 1
memory: 1Gi
requests:
cpu: 1
memory: 500M
deployment file of overlays/prod folder:
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
labels:
service: demo-app
name: demo-app
spec:
replicas: 1
selector:
matchLabels:
app: demo-app
template:
metadata:
labels:
service: demo-app
spec:
imagePullSecrets:
- name: my-docker-secret
containers:
- name: demo-app
image: the-my-app
imagePullPolicy: Always
ports:
- containerPort: 1234
resources:
limits:
cpu: 1
memory: 1Gi
requests:
cpu: 1
memory: 500M
Kustomization file of overlays/prod:
apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
resources:
- ../../base
patches:
- path: deployment.yaml
target:
kind: Deployment
options:
allowNameChange: true
namespace: prod-demo-app
images:
- name: the-my-app
newName: my.docker.registry.com/my-project/my-app
newTag: test
I suggest you use Helm, a much more robust templating engine. You can also use a combination of both Helm and Kustomize, Helm for templating and Kustomize for resource management, patches for a specific configuration, and overlays.