How to kustomize resouce in k8s? - kubernetes

Question

Assume I have cronjob 、service and deployment just like below:
# Create a directory to hold the base
mkdir base
# Create a base/deployment.yaml
cat <<EOF > base/deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
name: my-nginx
spec:
selector:
matchLabels:
run: my-nginx
replicas: 2
template:
metadata:
labels:
run: my-nginx
spec:
containers:
- name: my-nginx
image: nginx
EOF
# Create a base/service.yaml file
cat <<EOF > base/service.yaml
apiVersion: v1
kind: Service
metadata:
name: my-nginx
labels:
run: my-nginx
spec:
ports:
- port: 80
protocol: TCP
selector:
run: my-nginx
EOF
# Create a base/cronjob.yaml file
cat <<EOF > base/cronjob.yaml
apiVersion: batch/v1
kind: CronJob
metadata:
name: hello
spec:
schedule: "*/1 * * * *"
jobTemplate:
spec:
template:
spec:
containers:
- name: hello
image: busybox
imagePullPolicy: IfNotPresent
command:
- /bin/sh
- -c
- date; echo Hello from the Kubernetes cluster
restartPolicy: OnFailure
EOF
# Create a base/kustomization.yaml
cat <<EOF > base/kustomization.yaml
resources:
- deployment.yaml
- service.yaml
- cronjob.yaml
EOF
Normally, everything is working fine, but sometime my project don't require to run a cronjob, so I want to disable the cronjob.yaml import.
So, Is there a way to do that? for example like the jinja2,
- deployment.yaml
- service.yaml
{{ IF set CRONJOB }}
- cronjob.yaml
{{ ENDIF }}
I Understand #AniAggarwal posted, i can use a filter before run my kubectl apply -f but it no a very good for my project.
Any suggestions are welcome.

Answer 1

Assume the following is your file that gets generated after kustomize command. And the service is supposed to be conditional like your cronjob.
kind: Pod
apiVersion: v1
metadata:
name: echo-app
labels:
app: demo
spec:
containers:
- name: nginx
image: nginx
## if/end data.values.service.enabled:
---
kind: Service
apiVersion: v1
metadata:
name: echo-service
spec:
selector:
labels:
app: name
ports:
- name: port
port: 80
You can pipe the output of Your kustomize command to ytt to add or remove the service.
kustomize build | ytt --data-value service.enabled=false -f - | kubectl apply -f -
Checkout the project playground for another example
https://carvel.dev/ytt/#playground
https://github.com/vmware-tanzu/carvel-ytt/blob/develop/examples/data-values/run.sh
Hope it is the solution you're looking for. Good luck!