[Bug] Documenting how to make this container work if you are hosting docker on NixOS about docker-makemkv HOT 1 CLOSED

I have a solution! The reason I am posting here is so that anyone looking for a solution can find it easier once this is closed.

NixOS when installed on a 'bare metal' machine doesn't expose the 'sg' devices at all. At first I thought this was a docker specific issue, but it turns out that the problem is NixOS itself - docker is innocent.

This forum post: https://discourse.nixos.org/t/makemkv-cant-find-my-usb-blu-ray-drive/23714 captures the problem and the solution. I will repeat here.

In the naive install / broken state - the lsscsi -g command shows the problem

$ lsscsi -g
[0:0:0:0]    cd/dvd  ASUS     DRW-1814BL       1.10  /dev/sr0   -        
[3:0:0:0]    cd/dvd  HL-DT-ST BDDVDRW CH12LS28 1.00  /dev/sr1   -     
[.. other drives cut...]   

Yeah - so the - is the issue here. We expect that there should be /dev/sgY devices listed.

We can manually fix this with this command on the NixOS host

$ sudo modprobe sg

This will cause /dev/sg0 and /dev/sg1 to appear (or did on my system)

Then the docker container will work.

If you want your NixOS install to be fixed properly - you need to add the following to your /etc/nixos/configuration.nix file

  # Add missing kernel mods to create /dev/sgY devices
  boot.kernelModules = [ "sg" ];

Now your installation will always have the /dev/sgY devices that MakeMKV requires.

from docker-makemkv.