Newby question

I'm not sure what exactly is happening, but it may be that onInit() gets called before the networking code is fully initialized. The following will do what you're looking for:

var http = require("http");

function server() {
  http.createServer(function (req, res) {
    res.writeHead(200);
    res.end("Hello World");
  }).listen(8080);
}

function onInit() {
  Serial2.write("onInit\n");
  setTimeout(server, 1000);
}

The Serial2.write appears on uart1 (as opposed to the normal uart0) where the log messages are. You can remove that, I used it to see when onInit runs.