Music Sync

I have 2 wonderful children and for Xmas they received a Toniebox [1]. There are many incredbile Tonie's out there, but we were struggling with what we can fill our Creative Tonies. After a while we found many wonderful stories for kids on Spotify [2] and we wondered why not having these stories on a Creative Tonie.

In the end, this handy tool was created to sync music between different services. It supports plugins which helps in extending it for other input & output services.

Links:
[1]: https://www.tonies.com/
[2]: https://www.spotify.com/

Build

... To build the application to: package/application/target

mvn clean install

... To build a docker image whose execution and configuration files can be found at: package/docker/src/main/resources/docker/application

mvn clean install -Pdocker

Configuration

The configuration is provided in a JSON format for easier read- and accessibility. There for, it is split in 3 major parts.
Full example file can be found at: package/docker/src/main/resources/docker/application/config/musicsync.json

1. General - defines global configurations which are valid for the whole application
   An example of this is:

"general": {
  "timeout": 60,                    // nap time for the loop
  "bulk": true                      // upload all tracks as a bulk or do it one by one
} 

2. Plugins - configures global plugin settings
   An example of this is - see details on plugin documentations:

"plugins": 
[
  {
    "plugin": "<PLUGIN NAME>",      // name of the plugin
    "config": {}                    // configuration of plugin
  }
]

3. Connections - configures the synchronization connection (from where to where the music shall be synced)
   An example of this is:

"connections": 
[
    {
      "name": "<CONNECTION NAME>",  // name of configuration
      "in": {
        "plugin": "<PLUGIN NAME>",  // input plugin to source tracks
        "config": {}                // input plugin configuration to source tracks
      },
      "out": {
        "plugin": "<PLUGIN NAME>",  // output plugin to which the tracks shall be copied to
        "config": {}                // output plugin configuration to upload tracks
      }
    }
]

Execution

The application can be executed as standalone application or within a docker image which is provided by the maven build

Application

The standard maven build copies the full build output to: package/application/target.
This output will consist out of:

• libs - containing all necessary JAR files for the classpath
• modules - contains all necessary JAR files for the Java modules
• musicsync - BASH script file to start musicsync
• sp - file for stream recording. Must be copied to /usr/bin or /usr/local/bin. Chmod 755 is required
• stream_recorder.pl file for stream recording. Most be copied to /usr/bin or /usr/local/bin. Chmod 755 is required
• musicsync-*.jar files - the actual Java code of musicsync

If you move the directory's content to other folders and want to run the application with relative or absolute paths you have to update package/application/target/musicsync.

#!/bin/bash 

execdir=.     # THIS PATH HAS TO BE SPECIFIED/ADAPTED

classpath=$(find $execdir -name '*.jar' | awk '{ printf("%s:", $1); } END { printf("%s", $1); }')
executable='rocks.voss.musicsync.application/rocks.voss.musicsync.application.Application'

java -classpath $classpath -p $execdir:$execdir/modules -m $executable  $@

Docker Image

While using the docker profile of maven 2 docker images will be created.

1. Base image (maximilianvoss/musicsyncbase)
   This base image will base on Ubuntu 20.04 and will install Spotify and Oracle's JDK11.
   Please review the documentation at package/docker/src/main/resources/docker/base/README.md to ensure the docker image can be build.
2. Application image (maximilianvoss/musicsyncapplication)
   This image is based on maximilianvoss/musicsyncbase and will compile and install musicsync within the image.
   During the image execution following folder is shared from the host with the image: package/docker/src/main/resources/docker/application/config

Steps which must be performed to create a proper Docker image

1. Download JDK 11 from Oracle
2. Copy JDK 11 to package/docker/src/main/resources/docker/base
3. Build project with mvn clean install -Pdocker
4. Change dir to package/docker/src/main/resources/docker/application/config
   1. Update musicsync.json (maybe you have to run musicsync locally first to update Spotify settings)
   2. Update spotify
   3. Update vnc
5. Run docker image using ./run.sh in folder package/docker/src/main/resources/docker/application

Plugins

All plugins with their documentation can be found at plugins/README.md.

Known Issues

Spotify Repository Public Key missing
Indicator:

Reading package lists...
W: GPG error: http://repository.spotify.com stable InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 5E3C45D7B312C643
E: The repository 'http://repository.spotify.com stable InRelease' is not signed.
The command '/bin/sh -c apt-get update' returned a non-zero code: 100
Sending build context to Docker daemon  15.36kB
Step 1/12 : FROM maximilianvoss/musicsyncbase
pull access denied for maximilianvoss/musicsyncbase, repository does not exist or may require 'docker login': denied: requested access to the resource is denied
[ERROR] Command execution failed.

Resolution:
Retry after a certain amount of time - sometimes days. This is an error on Spotify's server infrastructure.