serveHandler function
Serves handler on InternetAddress.anyIPv4 using the port returned by
listenPortFromEnvironment.
The returned Future will complete using waitForTerminate after closing the server.
Implementation
Future<void> serveHandler(Handler handler) async {
final port = listenPortFromEnvironment();
final server = await serve(
handler,
InternetAddress.anyIPv4, // Allows external connections
port,
);
print('Serving at http://${server.address.host}:${server.port}');
await waitForTerminate();
await server.close();
}