How to copy files between pods or execute in a pod?
Actually I think your question is that you want to execute the command "cat readme" inside container right?
For this there should be a copy of that file present inside the container
For this you can use hostpath so that to mount the part that contains that file onto the node in a particular directory
you can use this for reference https://kubernetes.io/docs/concepts/storage/volumes/#hostpath
But the problem with this is you have to copy that directory with files present to all the nodes