Short version:
-
Download and build https://github.com/syncthing/discosrv, or download the binary for Linux linked from there.
-
Run that binary on the machine that is supposed to be your discovery server. Just
discosrv
without parameters is good enough to start with, otherwise seediscosrv -help
for the tweakables. -
Configure your syncthing instances to use
<your-discovery-box-ip>:22026
as global discovery server (settable in the GUI or config.xml).
That’s all.