With a new Pulseaudio server (I'm currently running 13.99, but I understand this applies for version 12 and above), having the cookie is no longer sufficient to allow the Pulseaudio clients to connect.

I've worked around the problem with the same technique as described in the x11docker issue #71 - creating an anonymous one-use pulseaudio socket and mounting it instead of the primary socket.

My run script looks something like this:

DOCKERID=${RANDOM} # or some other value that makes sense, for example - a counter
pasocket=$(pactl load-module module-native-protocol-unix socket=$HOME/.config/pulse/docker-socket$DOCKERID auth-anonymous=1)
docker run ... -v $HOME/.config/pulse/zoiper-socket$DOCKERID:/home/user/.pulse.socket ...
# after run
pactl unload-module $pasocket
rm -f $HOME/.config/pulse/zoiper-socket$DOCKERID

[ user is the user name of the unprivileged user inside docker]

The /etc/pulse/client.conf has to be updated, but that is not enough for command line utilities such as pacat - these need to also have the PULSE_SERVER environment variable set to unix:/home/user/.pulse.socket. I solved this by tacking an export at the end of /home/user/.bashrc. I check that this works well for the GUI applications I'm running in the docker.

Hello,
Firstly thanks for publishing this it's really useful. I've been using it as a starting point trying to get pulseaudio in docker working on some other applications. One weird thing I've discovered is that passing the X11 socket and DISPLAY variable to docker causes a "pa_context_connect() failed: Connection refused", as the applications I'm working on are GUI apps I clearly need to be able to pass this info.

For example, if I do:

docker run -it --rm -v /run/user/1000/pulse:/run/user/1000/pulse thebiggerguy/docker-pulseaudio-example

I see

Opening a playback stream with sample specification 's16le 2ch 44100Hz' and channel map 'front-left,front-right'.
Connection established.
Stream successfully created.
Buffer metrics: maxlength=4194304, tlength=352800, prebuf=349276, minreq=3528
Using sample spec 's16le 2ch 44100Hz', channel map 'front-left,front-right'.
Connected to device alsa_output.pci-0000_01_00.1.hdmi-stereo-extra1 (index: 1, suspended: no).
Stream started.

And hear lovely loud noise from /dev/urandom on my host

However if I do:

docker run -it --rm -e DISPLAY=unix$DISPLAY -v /tmp/.X11-unix:/tmp/.X11-unix -v /run/user/1000/pulse:/run/user/1000/pulse thebiggerguy/docker-pulseaudio-example

That is to say I include the option -e DISPLAY=unix$DISPLAY -v /tmp/.X11-unix:/tmp/.X11-unix in the docker run I see:

Opening a playback stream with sample specification 's16le 2ch 44100Hz' and channel map 'front-left,front-right'.
Connection failure: Connection refused
pa_context_connect() failed: Connection refused

I don't suppose that you could point me at what I might be missing? Google searches seem to be a bit light when it comes to the subject of pulseaudio from docker, which is what led me here in the first place.

Many thanks in advance.

I tried running the minimal sample with either root or not (not that as non-root from within the container the user cannot access the pulse socket):

$ docker run -it --user root --volume=/run/user/$(id -u)/pulse:/run/user/1000/pulse thebiggerguy/docker-pulseaudio-example
Opening a playback stream with sample specification 's16le 2ch 44100Hz' and channel map 'front-left,front-right'.
Connection failure: Access denied

Else this would allow to simplify https://github.com/wernight/docker-mopidy