Executing commands in one container from another

I am trying to get Beets to run on a Lidarr import with both Lidarr and Beets running in Docker Containers on an Ubuntu host. It looks like a permission issue or a setup issue with one or both of the containers.

I followed the instructions found here:
Beets + Lidarr

90-config and beet_import.sh are both in the Lidarr config folder. I can execute docker exec inside the Lidarr container and run docker commands so it seems like the 90-config is working properly in the Lidarr container.

The test in Lidarr when setting up the connection fails with the error:
Error|beet_import.sh|unreadable file: /dev/core

/dev/core is a link to /proc/kcore on the beets container.

/dev/core permissions inside beets container

lrwxrwxrwx 1 root root 11 Dec 29 12:40 core -> /proc/kcore

/proc/kcore permissions inside beets container

crw-rw-rw- 1 root root 1, 3 Dec 29 12:40 kcore

I am not able to change permission on the dev/core or /proc/kcore as root or as abc which is not surprising.
Running out of ideas what to try next.

Beets container config
docker create --name=beets -e TZ=America/Chicago -e PUID=1000 -e PGID=1000 -e LANG=en_US.UTF-8 -p 8337:8337 -v ~/Documents/Docker/beets:/config -v /mnt/kdrive/xbmc/Music:/music -v /mnt/cdrive/Users/user/Downloads/complete/music:/downloads linuxserver/beets:latest

Lidarr container config
docker create --name=lidarr -e TZ=America/Chicago -p 8686:8686 -e PUID=1000 -e PGID=1000 -v /mnt/cdrive/Users/user/Documents/Docker/lidarr/config/90-config:/etc/cont-init.d/90-config -v /var/run/docker.sock:/var/run/docker.sock -v /mnt/cdrive/Users/user/Documents/Docker/lidarr/config:/config/ -v /mnt/cdrive/Users/user/Downloads:/downloads/ -v /mnt/cdrive/Users/user/Downloads:/downloads-amd/ -v /mnt/kdrive/xbmc/Music:/music linuxserver/lidarr:nightly


  • Docker host is running Linux version 5.4.0-58-generic (buildd@lcy01-amd64-004) (gcc version 9.3.0 (Ubuntu 9.3.0-17ubuntu1~20.04)) #64-Ubuntu SMP Wed Dec 9 08:16:25 UTC 2020
  • Lidarr version is
  • Docker version is 20.10.1, build 831ebea
  • Beets version 1.4.9
  • Python version 3.8.2