如何从 Docker 容器访问 JACK 音频

Question

I have a multimedia app in a Docker container. I would like connect it to my JACK audio server running in the host system. How can I do it?

This is my current (and not working) docker run command:

    docker run \
        --rm \
        -i -t \
        -u $(id -u):$(id -g) \
        -v $(pwd):/home/app/build \
        -v $HOME:/home/app \
        -v /media:/media \
        -v /usr/local/lib64:/usr/local/lib64 \
        -v /tmp/.X11-unix:/tmp/.X11-unix \
        -v /etc/machine-id:/etc/machine-id \
        -v /run/user/$(id -u)/pulse:/run/user/$(id -u)/pulse \
        -v $HOME/.pulse:/home/app/.pulse \
        --env DISPLAY \
        --env HOME='/home/app' \
        --privileged \
        --group-add $(getent group audio | cut -d: -f3) \
        --name "app" \
        <image name> <parameters>

Answer 1

From this :

SHared Memory Another from of IPC used is shared memory. The base class for all shared memory in the JACK system is JackShmMemAble. Objects that need to go to shared memory need to derive from this base class. The implementation of this class is again platform dependent. For Linux systems the System V shared memory API's are made use of. The shared memory is used for a variety of purposes like notifying the client RT thread of what priority it must set itself to. Template classes JackShmReadWritePtr, JackShmReadWritePtr1 and JackShmReadPtr are made use of to access shared memory.

So, I think you should bind mount /dev/shm to container like next, then I guess the client in container could communicate with the jack audio server in host with shared memory:

docker run \
    --rm \
    -i -t \
    -u $(id -u):$(id -g) \
    -v /dev/shm:/dev/shm \
    -v $(pwd):/home/app/build \
    -v $HOME:/home/app \
    -v /media:/media \
    -v /usr/local/lib64:/usr/local/lib64 \
    -v /tmp/.X11-unix:/tmp/.X11-unix \
    -v /etc/machine-id:/etc/machine-id \
    -v /run/user/$(id -u)/pulse:/run/user/$(id -u)/pulse \
    -v $HOME/.pulse:/home/app/.pulse \
    --env DISPLAY \
    --env HOME='/home/app' \
    --privileged \
    --group-add $(getent group audio | cut -d: -f3) \
    --name "app" \
    <image name> <parameters>

Answer 2

Have you tried with docker run --ipc=host (...) ?

I think documentation refers to shared memory in the context of IPC. I guess --ipc=host has some security implications (since the container will have access to all IPC on the host for the running user). Also, maybe you'll need to run the process in the docker container with the same UID than the user on your host.

Answer 3

You'll want to use

 --device /dev/snd:/dev/snd

working with sound in docker