build: fix travis tests to use docker mysql-server

Author: dougwilson

.travis.yml

@@ -65,10 +65,11 @@ before_install:
 
   # Setup environment
   - "export MYSQL_DATABASE=node_mysql"
+  - "export MYSQL_PORT=$(node tool/free-port.js)"
   - "export MYSQL_USER=root"
 
 install:
-  - "docker run -d --name mysql -e MYSQL_ALLOW_EMPTY_PASSWORD=yes -e MYSQL_DATABASE=$MYSQL_DATABASE $DOCKER_MYSQL_TYPE:$DOCKER_MYSQL_VERSION"
+  - "docker run -d --name mysql -e MYSQL_ALLOW_EMPTY_PASSWORD=yes -e MYSQL_DATABASE=$MYSQL_DATABASE -p $MYSQL_PORT:3306 $DOCKER_MYSQL_TYPE:$DOCKER_MYSQL_VERSION"
   - "npm install"
   - "docker run --link mysql:db -e CHECK_PORT=3306 -e CHECK_HOST=db giorgos/takis"
 

tool/free-port.js

@@ -0,0 +1,47 @@
+var Net = require('net');
+
+var PORT_END    = 60000;
+var PORT_START  = 1000;
+var TCP_TIMEOUT = 1000;
+
+process.nextTick(run);
+
+function check(port, callback) {
+  var socket = Net.createConnection(port, 'localhost');
+  var timer  = setTimeout(function () {
+    socket.destroy();
+    callback(undefined);
+  }, TCP_TIMEOUT);
+
+  socket.on('connect', function () {
+    clearTimeout(timer);
+    socket.destroy();
+    callback(true);
+  });
+
+  socket.on('error', function (err) {
+    clearTimeout(timer);
+    if (err.syscall === 'connect' && err.code === 'ECONNREFUSED') {
+      callback(false);
+    } else {
+      callback(undefined);
+    }
+  });
+}
+
+function run() {
+  function next() {
+    var port = PORT_START + Math.floor(Math.random() * (PORT_END - PORT_START + 1));
+
+    check(port, function (used) {
+      if (used === false) {
+        console.log('%d', port);
+        process.exit(0);
+      } else {
+        setTimeout(next, 0);
+      }
+    });
+  }
+
+  next();
+}