Fix #1564: Use Procfile for process types in Dockerfile apps

* Document new Procfile feature
* Add and update tests
* Fix a typo in generate_scale_file (ref #1923)

tests/apps/dockerfile-procfile/CHECKS

@@ -0,0 +1 @@
+/ nodejs/express

tests/apps/dockerfile-procfile/Dockerfile

@@ -0,0 +1,16 @@
+FROM ubuntu:trusty
+ENV LC_ALL C
+ENV DEBIAN_FRONTEND noninteractive
+ENV DEBCONF_NONINTERACTIVE_SEEN true
+EXPOSE 3001/udp
+EXPOSE  3000/tcp
+EXPOSE 3003
+
+RUN apt-get install -y software-properties-common && add-apt-repository ppa:chris-lea/node.js && apt-get update
+RUN apt-get install -y build-essential curl postgresql-client-9.3 nodejs git
+
+COPY . /app
+WORKDIR /app
+RUN npm install
+
+CMD npm start

tests/apps/dockerfile-procfile/Procfile

@@ -0,0 +1,8 @@
+###############################
+#         DEVELOPMENT         #
+###############################
+
+# Procfile for development using the new threaded worker (scheduler, twitter stream and delayed job)
+cron: node worker.js
+web: node web.js
+worker: node worker.js

tests/apps/dockerfile-procfile/check_deploy

@@ -0,0 +1,2 @@
+#!/usr/bin/env bash
+set -e; output="$(curl -s -S "$1")"; echo "$output"; test "$output" == "nodejs/express"

tests/apps/dockerfile-procfile/package.json

@@ -0,0 +1,13 @@
+{
+  "name": "node-example",
+  "version": "0.0.1",
+  "dependencies": {
+    "express": "2.5.x"
+  },
+  "engines": {
+    "node": "4.2.x"
+  },
+  "scripts": {
+    "start": "false"
+  }
+}

tests/apps/dockerfile-procfile/web.js

@@ -0,0 +1,12 @@
+var express = require('express');
+
+var app = express.createServer(express.logger());
+
+app.get('/', function(request, response) {
+  response.send('nodejs/express');
+});
+
+var port = process.env.PORT || 5000;
+app.listen(port, function() {
+  console.log("Listening on " + port);
+});

tests/apps/dockerfile-procfile/worker.js

@@ -0,0 +1,6 @@
+function worker() {
+  console.log('sleeping for 60 seconds');
+  setTimeout(worker, 60 * 1000);
+}
+
+worker();