A Spring Boot application which serves a REST API for the metadata produced by shairport-sync.
It also:
- Looks up the beats-per-minute value for the playing track using songbpm.com and includes this in the API response.
- Sends the BPM value, once received, to a target REST endpoint. I'm using this in conjunction with my traffic light project.
The metadata reading component is based on the C code in the upstream repo, the rest of it is customised for my own needs.
The shairport-sync server needs to have been built with the flag --with-metadata so that the reader will have some content to consume. Refer to the section https://github.com/mikebrady/shairport-sync/blob/master/INSTALL.md#build-and-install for an example, but including the extra parameter.
Clone this repo and build using mvn clean install. Run the executable .jar file in the /target subdirectory.
I installed the Spring Boot application as an init.d service (see this guide) which makes it easy to start, stop and gather logs.
I'm using GitHub Actions and the master-branch workflow to automatically version the build products, and deploy this to my local device.
Set the environment variable SPRING_PROFILES_ACTIVE=production to use songbpm.com rather than the default dummy lookup.
See application.properties for sample configuration. If you also have a funny traffic light in your home, and want to use it, you will need to customise the visualiser.baseurl parameter.
When the application runs, API docs are served by springdoc-openapi at /docs. These are fully interactive so you can explore and test out the API as it runs.
Separately, data is sent to the visualiser using a JSON blob of the form
{
"bpm" : 123
}