I have a deployment that creates pods on demand with an image and a volume mounted to it.
I have to exec a command in the pod to start up the service, but only once the node is running (hence why I am not doing it in the docker image).
How can I run a command inside the pod from outside (ie like a .sh file I can run from outside the cluster that will exec into the pods and run the command?)
Update: I found that using the command: header in the yaml will allow you to overwrite the ENTRYPOINT in the Dockerfile. See here
My new issue is that i don't know which is first; the volume being mounted or the command being run (I assume the latter). I need to have some contents from the volume before i can run the command. Any advice will be appreciated.
$ kubectl exec --help
Execute a command in a container.
Options:
-c, --container='': Container name. If omitted, the first container in the pod will be chosen
-p, --pod='': Pod name
-i, --stdin=false: Pass stdin to the container
-t, --tty=false: Stdin is a TTY
Usage:
kubectl exec POD [-c CONTAINER] -- COMMAND [args...] [options]Addition to Alex's answer
If you have multiple Containers in your Pod, you need to specify Container name, otherwise, you will exec into first Container.
kubectl exec -it -n <namespace-name> <pod-name> -c <container-name> -- COMMAND [args...]Read details about kubectl exec
For the initial question, something like the following would work:
kubectl exec -it pod --namespace=namespace cat /etc/hostsObviously change the pod name, namespace and command.
With regards to your update, the volume is created first, I know from mounting persistent storage for mongo containers then on startup the mongo entrypoint writes data to this location.