Table of Contents

• Docker Madsonic 5.2
  • Features
• Building image
• Running container
  • Just run
  • Configuration
  • Recommended use
  • Logs
• Troubleshooting
  • No UTF-8 support
  • [Properly starting and stopping Madsonic](#properly-starting-and-stopping-madsonichttpwwwmadsonicorg)
• Thanks to
• Todo

Docker Madsonic 5.2

Docker image of Madsonic 5.2.5420 build on Debian Jessie using supervisor to bootstrap and run Madsonic.

Features

• Lightweight Debian based
• Supervisor process management
• UTF-8 support
• Exposes most of the Madsonic configuration options through environmental variables

Building image

$ git clone
$ sudo docker build -t bremme/madsonic

Running container

Just run

$ sudo docker run \
    --volume=/my_music_dir:/var/media/artists \
    --publish=4040:4040 \
    --name madsonic \
    --detach \
    bremme/madsonic

Configuration

Madsonic can be configured through environmental variables. These variables can be pased to the Docker run command using the --env=VARIABLE=value switch or loaded from a file using the --env-file=my_env_file.env switch. Avaliable variables are:

Variables	Default	Description
MAD_HOST	0.0.0.0	Hostname/ip address
MAD_PORT	4040	HTTP port
MAD_HTTPS_PORT	0	HTTPS port (0 = disabled)
MAD_CONTEXT_PATH	/	The last part of the madsonic URL
MAD_INIT_MEM	192	Init Java heap size in megabytes
MAD_MAX_MEM	384	Max Java heap size in megabytes
MAD_TIME_ZONE	Europe/Amsterdam	Timezone
MAD_UID	1000	madsonic UID
MAD_GID	1000	madsonic GID

If you are mounting a music directory from your host machine and you want Madsonic to be able to change album art and tags, MAD_UID and MAD_GID should match the UID and GID of the music directory on the host machine.

So if you music collection is stored at /home/foo/music and the uid of foo is 1020 and the gid 1035 you should start Madsonic with:

$ sudo docker run \
    --env=MAD_UID=1020 \
    --env=MAD_GID=1035 \
    --volume=/home/foo/music:/var/media/artists \
    --publish=4040:4040 \
    --name madsonic \
    --detach \
    bremme/madsonic

Recommended use

I like to store application state in a separate data only volume. You can mount volumes from a (data) container using the --volumes-from switch. If you don't want to run a separate container, but want to preserve state. You should either build the image or run the container with a volume /var/madsonic.

docker run \
    --env=MAD_UID=1000 \
    --env=MAD_GID=1000 \
    --volumes-from=data-madsonic \
    --volume=/my_music_dir:/var/media/artists \
    --volume=/etc/timezone:/etc/timezone:ro \
    --publish=49155:4040 \
    --name madsonic \
    --restart=always \
    --detach=true \
    bremme/madsonic

Logs

Madsonic will log to three places:

• stdout goes to: /var/log/supervisor/madsonic.stdout.log
• stderr goed to: /var/log/supervisor/madsonic.stderr.log
• madsonic's own log goes to: /var/madsonic/madsonic.log

You can follow the logs for debugging by:

$ sudo docker exec -it madsonic \
    tail -f \
        /var/log/supervisor/madsonic.stdout.log \
        /var/log/supervisor/madsonic.stderr.log  \
        /var/madsonic/madsonic.log

Troubleshooting

During building the Madsonic image I ran into several problems. All of them should be fixed in this image. But perhaps you run into similair problem for whatever reason. Here are some of the things I did to solve the problems I encountered.

No UTF-8 support

Some of the tracks in my music collection contain characters not in the default C.UTF-8 locale (like ä, ö, ü, ..). I search for how to properly fix this, and found numerous solutions, this is what I eventually applied and works.

# fix language
RUN apt-get update && \
    apt-get install locales && \
    echo "en_US.UTF-8 UTF-8" >> /etc/locale.gen && \
    locale-gen

ENV LC_ALL=en_US.UTF-8 \
    LANG=en_US:en \
    LANGUAGE=en_US.UTF-8

The ouput of locale -a is now:

$ locale -a
C
C.UTF-8
en_US.utf8
POSIX

Adding or uncommenting en_US.UTF-8 UTF-8 to/from /etc/locale.gen incombination with locale-gen generates the new locale. You can check if it properly installed by locale -a. Setting the locale environmental variables afterward does not result in any error and your new locale is properly configured.

Properly starting and stopping Madsonic

First, if you are familiar with supervisor this is nothing new. But if not, this is how it works.

1. The Supervisor deamon reads all config files in /etc/supervisor/conf.d/*
2. These config files launch a script or binairy (mine are at /usr/local/bin/)
3. In case of Madsonic this bash script launches Madsonic which is a Java application.

I need the bash script for bootstrapping Madsonic, but I don't want it to spawn another process. The key is using exec. exec replace the shell with a given program (executing it, not as new process) and that's what I needed.

For now I use the default SIGTERM signal to stop Madsonic. I'm not totally sure if this is real gracefull shutdown, but works for now.

Thanks to

Building this image I used to following repro's for inspiration:

binhex/arch-madsonic botez/docker-madsonic sdhibit/docker-madsonic plytro/docker-madsonic

Todo

• Pulseaudio pass through (Madsonic keeps crasing when I change tracks)