http.Server doesn't expose randomly selected port

If you specify port 0, as serve({ port: 0 }) the library works correctly and automatically selects a port. However, the port is accessible to the process cannot advertise where it is listening on. In some cases it is desirable to start a process on any available port, and then advertise it, be it through the console, or some other transport/file.

[AaronO]

@aricart @getspooky You can actually already do this, though it’s somewhat quirky (.port and Addr typing), see https://github.com/denoland/deno/pull/11410#issuecomment-880747416:

import { serve } from "https://deno.land/std@0.101.0/http/server.ts";
const server = serve({ port: 0 });
const serverAddr = server.listener.addr as Deno.NetAddr;
console.log(`http://localhost:${serverAddr.port}`);
for await (const req of server) {
  req.respond({ body: "Hello World\n" });
}

[kt3k]

@iuioiua Thanks. Right, this was resolved in #2311. Now the listening port is available in the option of onListen handler.