Fix docker shell history navigation

2-minute read
docker • shell • linux

Prerequisites

  1. Start a docekr container:
docker run --rm -it alpine sh
  1. Run some random commands in that shell:
ls -la
pwd
cd ~
uname -a

Problem

Try to navigate the history with Ctrl + p and notice it is broken. When you press it the first time it does nothing, press it a second time it jumps 2 commands.

Reason

  • The first time you press Ctrl + p, it waits to see if you press Ctrl + q to detach from the docker container.
  • The second time you press Ctrl + p, it notices you did not press Ctrl + q, so it issues both escape sequences to the shell, navigating you 2 positions back in the command history.

Pause

Yes I know, docker devs should have chosen a sequence not already reserved by literally all shells ever, but don’t blame just them, vim, emacs, tmux, and more, do this sort of common sense clobbering too. And they won’t change defaults because they’re too big and arrogant to care.

Solution

Add this key to your ~/.docker/config.json:

"detachKeys": "ctrl-@"

It should look something like:

{
  "HttpHeaders": {
    "User-Agent": "Docker-Client/19.03.13-ce (linux)"
  },
  "detachKeys": "ctrl-@"
}

Now you:

  • Press Ctrl + p and what should have always happened, will happen.
  • Hit Ctrl + Shift + @ to detach, instead of Ctrl + p | Ctrl + q.