From b9c65f2d5882ad7cbd29c47ef3a599c29a1cd322 Mon Sep 17 00:00:00 2001
From: Jonathan Rainville <rainville.jonathan@gmail.com>
Date: Thu, 23 Aug 2018 15:11:43 -0400
Subject: [PATCH] use listen(0) to find a port

---
 lib/modules/webserver/index.js  | 21 ++++++++++++---------
 lib/modules/webserver/server.js | 14 ++++++++------
 2 files changed, 20 insertions(+), 15 deletions(-)

diff --git a/lib/modules/webserver/index.js b/lib/modules/webserver/index.js
index 8fd62d734..a0b948502 100644
--- a/lib/modules/webserver/index.js
+++ b/lib/modules/webserver/index.js
@@ -18,13 +18,15 @@ class WebServer {
 
     this.events.emit("status", __("Starting Server"));
 
+    this.server = new Server({host: this.host, port: this.port});
     this.testPort(() => {
-      this.server = new Server({host: this.host, port: this.port});
-
-      this.setServiceCheck();
       this.listenToCommands();
       this.registerConsoleCommands();
-      this.server.start((_err, message) => this.logger.info(message));
+      this.server.start((_err, message, port) => {
+        this.logger.info(message);
+        this.port = port;
+        this.setServiceCheck();
+      });
     });
   }
 
@@ -33,17 +35,18 @@ class WebServer {
       if (err) { // Port is ok
         return done();
       }
-      this.logger.warn(__('Webserver already running on port {{oldPort}}. Trying to connect on {{newPort}}',
-        {oldPort: this.port, newPort: this.port + 1}));
-      this.port++;
-      this.testPort(done);
+      this.logger.warn(__('Webserver already running on port %s. Assigning an available port', this.port));
+      this.port = 0;
+      this.server.port = 0;
+      done();
     });
   }
 
   setServiceCheck() {
-    let url = 'http://' + canonicalHost(this.host) + ':' + this.port;
+    const self = this;
 
     this.events.request("services:register", 'Webserver', function (cb) {
+      let url = 'http://' + canonicalHost(self.host) + ':' + self.port;
       utils.checkIsAvailable(url, function (available) {
         let devServer = __('Webserver') + ' (' + url + ')';
         let serverStatus = (available ? 'on' : 'off');
diff --git a/lib/modules/webserver/server.js b/lib/modules/webserver/server.js
index 40356be6b..340f5307c 100644
--- a/lib/modules/webserver/server.js
+++ b/lib/modules/webserver/server.js
@@ -24,12 +24,14 @@ class Server {
       serve(req, res, finalhandler(req, res));
     }).withShutdown();
 
-    let message = __("webserver available at") +
-                    " " +
-                    ("http://" + canonicalHost(this.hostname) +
-                    ":" + this.port).bold.underline.green;
-    this.server.listen(this.port, this.hostname);
-    callback(null, message);
+
+    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);
+    });
   }
 
   stop(callback) {