Execute bash command in pod with kubectl?

ghz 1years ago ⋅ 7013 views

Question

My question is simple.

How to execute a bash command in the pod? I want to do everything with a single bash command.

[root@master ~]# kubectl exec -it --namespace="tools" mongo-pod --bash -c "mongo"
Error: unknown flag: --bash

So, the command is simply ignored.

[root@master ~]# kubectl exec -it --namespace="tools" mongo-pod bash -c "mongo"
root@mongo-deployment-78c87cb84-jkgxx:/#

Or so.

[root@master ~]# kubectl exec -it --namespace="tools" mongo-pod bash mongo
Defaulting container name to mongo.
Use 'kubectl describe pod/mongo-deployment-78c87cb84-jkgxx -n tools' to see all of the containers in this pod.
/usr/bin/mongo: /usr/bin/mongo: cannot execute binary file
command terminated with exit code 126

If it's just a bash, it certainly works. But I want to jump into the mongo shell immediatelly.

I found a solution, but it does not work. Tell me if this is possible now? [Executing multiple commands( or from a shell script) in a kubernetes pod](https://stackoverflow.com/questions/43499313/executing-multiple-commands- or-from-a-shell-script-in-a-kubernetes-pod)

Thanks.

Answer

The double dash symbol "--" is used to separate the command you want to run inside the container from the kubectl arguments. So the correct way is:

kubectl exec -it --namespace=tools mongo-pod -- bash -c "mongo"

You forgot a space between "--" and "bash".

To execute multiple commands you may want:

  • to create a script and mount it as a volume in your pod and execute it

  • to launch a side container with the script and run it

#kubernetes