How to log into Docker from commandline

So I can get the Docker alpine linux terminal thing via:

screen ~/Library/Containers/com.docker.docker/Data/com.docker.driver.amd64-linux/tty

yet i’m having trouble figuring out what the default user/password is to login. Cant seem to find it in the docs.

Ah! Googleto the rescue.

The default login is root - no password. Maybe docs should be updated?