docker run attempts to mount a file I didn't ask for

Question

When I try to run an image without any mounts, why is Docker still trying to mount something that I didn't ask for?

docker run --rm myapp bash

docker: Error response from daemon: cannot mount volume over existing file, file exists /var/lib/docker/aufs/mnt/9326735ac6d36724bcb8e49ac2f0dd8288ad92ce385fe24ebaffc19a3a9c5756/etc/myapp.yml.

I have a running container that mounts this file, but why is Docker trying to mount it when I want to run a one-off command?

Answer 1

If I remember right, we had the same issue because of dangling volumes, as @Mohammed Noureldin said.

I couldn't delete the image, but this code worked fine for me https://coderwall.com/p/hdsfpq/docker-remove-all-dangling-volumes

Answer 2

I faced the same error before, I forget what I did exactly to get that, but the solution which worked for me is clear all the containers which uses the image "myapp", and remove any dangling volumes.

Then remove the base image "myapp" and rebuild (or download) it, and then retry to run your container.