webserver uses event and waterfall for triggering placeholder build, opening browser

lib/modules/webserver/index.js

@@ -24,8 +24,13 @@ class WebServer {
 
     this.events.emit("status", __("Starting Server"));
 
-    this.server = new Server({host: this.host, port: this.port});
+    this.server = new Server({
       buildDir: this.buildDir,
+      events: this.events,
+      host: this.host,
+      port: this.port
+    });
+
     this.testPort(() => {
       this.listenToCommands();
       this.registerConsoleCommands();

lib/modules/webserver/server.js

@@ -1,4 +1,5 @@
 let finalhandler = require('finalhandler');
+const async = require('async');
 let http = require('http');
 let serveStatic = require('serve-static');
 const {canonicalHost, defaultHost, dockerHostSwap} = require('../../utils/host');
@@ -8,6 +9,7 @@ require('http-shutdown').extend();
 class Server {
   constructor(options) {
     this.buildDir = options.buildDir;
+    this.events = options.events;
     this.port = options.port || 8000;
     this.hostname = dockerHostSwap(options.host) || defaultHost;
     this.isFirstStart = true;
@@ -27,21 +29,41 @@ class Server {
       serve(req, res, finalhandler(req, res));
     }).withShutdown();
 
+    const self = this;
 
-    this.server.listen(this.port, this.hostname, () => {
-      this.port = this.server.address().port;
-      callback(null, __("webserver available at") +
-        " " +
-        ("http://" + canonicalHost(this.hostname) +
-          ":" + this.port).bold.underline.green, this.port);
-      if (!this.opened) {
-        // fail silently, e.g. in a docker container, by cacthing promise
-        // rejection w/ a noop
-        opn(`http://${canonicalHost(this.hostname)}:${this.port}`)
-          .catch(function () {});
-        this.opened = true;
+    async.waterfall([
+      function createPlaceholderPage(next) {
+        if (self.isFirstStart) {
+          self.isFirstStart = false;
+          return self.events.request('embark-building-placeholder', next);
+        }
+        next();
+      },
+      function listen(next) {
+        self.server.listen(self.port, self.hostname, () => {
+          self.port = self.server.address().port;
+          next();
+        });
+      },
+      function openBrowser(next) {
+        if (!self.opened) {
+          self.opened = true;
+          const _next = () => { next(); };
+          // fail silently, e.g. in a docker container
+          return opn(
+            `http://${canonicalHost(self.hostname)}:${self.port}`,
+            {wait: false}
+          ).then(_next, _next);
+        }
+        next();
+      },
+      function reportAvailable(next) {
+        next(null, __("webserver available at") +
+             " " +
+             ("http://" + canonicalHost(self.hostname) +
+              ":" + self.port).bold.underline.green, self.port);
       }
-    });
+    ], callback);
   }
 
   stop(callback) {