@katexochen thanks, it solved that problem, now it runs \0/ ... but I can't access the service with my browser /0\ , I guess it's a purely docker issue now? I've added:
ExposedPorts = {
"8000/tcp" = {};
};
and 8000/tcp shows in docker ps and docker inspect, and that's the port the app binds to, but my browser says unable to connect on http://localhost:8000/ :'(

#nix #docker