Fire up an interactive bash Pod within a Kubernetes cluster

In those cases where you need a throw-away interactive shell within your cluster:

$ kubectl run my-shell --rm -i --tty --image ubuntu -- bash

You may, of course, use a different image or shell. Some of the arguments explained:

• my-shell: This ends up being the name of the Deployment that is created. Your pod name will typically be this plus a unique hash or ID at the end.
• --rm: Delete any resources we've created once we detach. When you exit out of your session, this cleans up the Deployment and Pod.
• -i/--tty: The combination of these two are what allows us to attach to an interactive session. 
• --: Delimits the end of the kubectl run options from the positional arg (bash).
• bash: Overrides the container's CMD. In this case, we want to launch bash as our container's command.

Note that you'll need to update your apt cache before you can install packages:

$ apt update
$ apt install cowsay

Once you are done with your tinkering:

$ exit

Post-exit, the Deployment and Pod that kubectl created will both be stopped and deleted, taking with it our container and anything we did within it.