alpine-pulseaudio

Container for Alpine Linux + S6 + PulseAudio + Bluez

This image containerizes the PulseAudio Network Sound server to setup a central sound service inside a local network, also runs the Bluez bluetooth daemon to work with bluetooth speakers or sources. Includes Pulsemixer to manage pulseaudio from CLI.

Based on Alpine Linux from the s6 image with the pulseaudio package installed in it.

Get the Image¶

Pull the image for your architecture if it's already available from Docker Hub.

docker pull woahbase/alpine-pulseaudio

Run¶

Running the container starts the service.

docker run --rm -it \
  --name docker_pulseaudio \
  -p 4713:4713 \
  --net=host \
  --cap-add NET_ADMIN \
  --device /dev/snd \
  --device /dev/bus/usb \
  -v $PWD/config/pulse:/etc/pulse \
  -v /var/run/dbus:/var/run/dbus \
  -v /etc/localtime:/etc/localtime:ro \
woahbase/alpine-pulseaudio:x86_64

docker run --rm --privileged multiarch/qemu-user-static --reset -p yes

Configuration¶

• This image runs PulseAudio under the user root, but also has a user pulse configured to drop privileges to the passed PUID/PGID which is ideal if its used to run in non-root mode. That way you only need to specify the values at runtime and pass the -u pulse if need be. (run id in your terminal to see your own PUID/PGID values.)

• PulseAudio config files read from /etc/pulse. If you have custom cards other than your default sound output jack, most likely you will need to edit or remount this with your own. For example, you can keep the files inside config/pulse and mount it as /etc/pulse on start.

• Does not run own systemd or dbus daemon so cards might not get detected automatically, default configuration loads only the defauls Alsa Sink, so will need to modify configurations to detect the new hardware.

• Default configuration listens to port 4713. Will need to have this port accessible from add devices to get sound. (Check your firewall).

• Bluetooth configurations read from /etc/bluetooth.

• To persist paired bluetooth configurations, preserve the contents of /var/lib/bluetooth by mounting it someplace like config/devices.

• DBUS can cause permission issues if the host is not configured to allow Bluez or PulseAudio. Host configuration defaults for these are provided inside /config/dbus.

• Any drivers for audio (and/or bluetooth as in Rasperry Pis) will need to be installed in the host machine.

• Don't forget to set the environment variable PULSE_SERVER as your server host in the client machines so that they forward their sound to the server. Check out this link for more information.

• To run only the pulseaudio server without starting bluetooth, set the environment variable DISABLEBLUETOOTH to the string true.

Stop the container with a timeout, (defaults to 2 seconds)

docker stop -t 2 docker_pulseaudio

Restart the container with

docker restart docker_pulseaudio

Removes the container, (always better to stop it first and -f only when needed most)

docker rm -f docker_pulseaudio

Shell access¶

Get a shell inside a already running container,

docker exec -it docker_pulseaudio /bin/bash

Optionally, login as a non-root user, (default is alpine)

docker exec -u alpine -it docker_pulseaudio /bin/bash

Or set user/group id e.g 1000/100,

docker exec -u 1000:100 -it docker_pulseaudio /bin/bash

Logs¶

To check logs of a running container in real time

docker logs -f docker_pulseaudio

Build Your Own¶

Feel free to clone (or fork) the repository and customize it for your own usage, build the image for yourself on your own systems, and optionally, push it to your own public (or private) repository.

Here's how...

Setting up¶

Before we clone the /repository, we must have Git, GNU make, and Docker (optionally, with buildx plugin for multi-platform images) setup on the machine. Also, for multi-platform annotations, we might require enabling experimental features of Docker.

Clone the repo with,

git clone https://github.com/woahbase/alpine-pulseaudio
cd alpine-pulseaudio

make -n <targetname> <optional args>

Build and Test¶

To create the image for your architecture, run the build and test target with

make build test 

For building an image that targets another architecture, it is required to specify the ARCH parameter when building. e.g.

make build test ARCH=aarch64 

make build test ARCH=armhf 

make build test ARCH=armv7l 

make build test ARCH=x86_64 

Make to Run¶

Running the image creates a container and either starts a service (for service images) or provides a shell (can be either a root-shell or usershell) to execute commands in, depending on the image. We can run the image with

make run 

But if we just need a root-shell in the container without any fance pre-tasks (e.g. for debug or to test something bespoke), we can run bash in the container with --entrypoint /bin/bash. This is wrapped in the makefile as

make shell 

There may be more such targets defined as per the usage of the image. Check the makefile for more information.

Push the Image¶

If the build and test steps finish without any error, and we want to use the image on other machines, it is the next step push the image we built to a container image repository (like /hub), for that, run the push target with

make push 

If the built image targets another architecture then it is required to specify the ARCH parameter when pushing. e.g.

make push ARCH=aarch64 

make push ARCH=armhf 

make push ARCH=armv7l 

make push ARCH=x86_64 

That's all folks! Happy containerizing!

Maintenance¶

Sources at Github. Images at Docker Hub.

Maintained (or sometimes a lack thereof?) by WOAHBase.