How to enter filesystem on docker container after computer crash?

Question

I had a running Docker container on a computer.

The computer crashed due to a power failure. The disk started up right etc, and now I want to go somehow go to the container and "salvage" the data from there. I know the container ID.

I can see the diffs in /var/lib/docker/aufs/diff ; however, I need the whole filesystem as it was during the crash, if possible.

In /var/lib/docker/aufs/mnt, I don't see a thing.

When I tried to run another docker with --with-volumes (ID), I see nothing there.

How to get to the actual data, as they were during the crash?

Answer 1

I am not sure if it's "the right way", but this helped me.

docker commit (ID of the crashed container)

This creates a new image out of the crashed container and gives me its ID. Now I just have to run the new image...

docker run -ti (ID of the new image)

and I can now safely salvage the data.

Answer 2

Posting this here as well for easy of googling. Originally posted here.

The easiest way I've found for copying from a non-functional container is docker cp.

docker cp <container-name>:<path/inside/container> <path/on/host/>

Thanks to docker cp (link) you can copy directly from the container as it was any other part of your filesystem. For example, recovering all files inside a container:

mkdir /tmp/container_temp
docker cp example_container:/ /tmp/container_temp/

Note that you don't need to specify that you want to copy recursively.