I am following documentation example at https://kubernetes.io/docs/concepts/workloads/pods/init-containers/#init-containers-in-use
I created following pod:
apiVersion: v1
kind: Pod
metadata:
name: myapp-pod
labels:
app: myapp
spec:
initContainers:
- name: init-myservice
image: busybox
command:
[
"sh",
"-c",
"until nslookup myservice; do echo waiting for myservice; sleep 2; done;",
]
- name: init-mydb
image: busybox
command:
[
"sh",
"-c",
"until nslookup mydb; do echo waiting for mydb; sleep 2; done;",
]
containers:
- name: myapp-container
image: busybox
command: ["sh", "-c", "echo The app is running! && sleep 3600"]but I did not create the services yet (myservice, mydb).
My expectation is for deployment to hold until I create services, but it just continues with deployment and creates the pod called "myapp-pod".
Am I missing something on this run?
Why it does not hold until I create the services?
This happens because you are using ash inside busybox and it has different behavior (not same as bash). So your script actually ends there.
You can try it inside busybox yourself:
kubectl run -i --tty busybox --image=busybox --restart=Never -- shAnd then use your command:
until nslookup myservice; do echo waiting for myservice; sleep 2; done;To fix this issue you can try something different, for example alpine.
kubectl run -i --tty alpine --image=alpine --restart=Never -- sh