Docker: attach to a specific bash

Lets say I have a container running and I do

docker exec -ti container-id /bin/bash

Then I detach from this container and want to attach again

If I do this

docker attach container-id

I wont go back to that bash that I created. Instead I will go to the main process.

How can I attach to that bash again ?

Answer

You can’t. While the docker exec documentation suggests it supports the same “detach” key sequence as docker run, the exec’d process doesn’t have any Docker-level identity (beyond its host and container pids) and there’s no way to re-attach to that shell.

(In the Docker API, “exec instance” is an actual object so this isn’t technically impossible; the CLI just has no support for it.)

The workflow you’re describing sounds more like what you’d run with screen or tmux in a virtual machine.