I started with this one:

https://medium.com/@icelain/a-guide-to-building-a-realtime-h...

And then, modified a lot. At some moment I will open it back. (Author's MIT license allowed closing it; I did it actually because I embedded a number of idiosyncrasies related to the radio service that shouldn't be disclosed; but with some amount of work it can be divided into an open and closed part).

The broadcasting skeleton from that original blog/github project is good, though! It might work for your case.

Please keep in mind it's better to stream AAC than MP3. Basically any format you'd probably want to use can be converted to AAC with ffmpeg.

AAC has a simple frame format and it's easy to decipher it; I use it to always send full frames, even when one would want to skip to the next song - by doing that the client behaves more smoothly.