I am trying to build a backup and restore solution for the Docker containers that we work with.
I have Docker base image that I have created, ubuntu:base
I just started using docker to compile VLC, here's what you can do to copy files back and forth from containers:
su -
cd /var/lib/docker
ls -palR > /home/user/dockerfilelist.txt
Search for a familiar file in that txt and you'll have the folder, cd to it as root and voila! copy all you want.
There might be a path with "merged" in it, I guess you want the one with "diff" in it.
Also if you exit the container and want to be back where you left off:
docker ps -a
docker start -i containerid
I guess that's usefull when you didn't name anything with a command like
docker run -it registry.videolan.org:5000/vlc-debian-win64 /bin/bash
Sure the hacker method but so what!