Heroku needs a server.js file. What to put in it? - node.js

Question

I'm working on a simple node app and all is working well on local. But when deploying on Heroku, I had an error.
The tutorial on Heroku tells to add on package.json
"scripts": {
"start": "node server.js"
},
But, what can I put in server.js ? I found lots of examples but nothing clear or relevant for me. I'm a bit confused about the need of this.
The setting of the app is quite common : npm install/bower install and then "grunt serve" to launch the app. The app is a simple HTML/Angular web app calling endpoints on an API.
NB : I'm not using Express.
Here is the gruntfile.js :
'use strict';
module.exports = function (grunt) {
// Load grunt tasks automatically
require('load-grunt-tasks')(grunt);
// Time how long tasks take. Can help when optimizing build times
require('time-grunt')(grunt);
// Configurable paths for the application
var appConfig = {
app: require('./bower.json').appPath || 'app',
dist: '../project/WebApp'
};
//Environment vars
var envConfig = {
dev: {
baseUrl: 'http://localhost:3000',
loginUrl: 'http://demo.lvh.me:9000'
},
prod: {
baseUrl: '',
loginUrl: ''
}
};
// Require ModRewrite object before initConfig
var modRewrite = require('connect-modrewrite');
// Define the configuration for all the tasks
grunt.initConfig({
appConf: appConfig,
// Empties folders to start fresh
clean: {
dist: {
files: [{
dot: true,
src: [
'.tmp',
'<%= appConf.dist %>/{,*/}*',
'!<%= appConf.dist %>/.git*'
]
}],
options: {
force: true //since dist directory is outside, we must use force flag.
}
},
server: '.tmp'
},
//server settings
ngconstant: {
// Options for all targets
options: {
space: ' ',
wrap: '\'use strict\';\n\n {%= __ngModule %}',
name: 'config'
},
// Environment targets
development: {
options: {
dest: 'app/config.js'
},
constants: envConfig.dev
},
production: {
options: {
dest: '<%= appConf.app %>/config.js'
},
constants: envConfig.prod
}
},
// Automatically inject Bower components into the app
wiredep: {
app: {
src: ['<%= appConf.app %>/index.html'],
ignorePath: /\.\.\//,
'options': {
'overrides': {
'semantic-ui': {
'main': ['dist/semantic.css', 'dist/semantic.js']
}
}
}
}
},
// Copies remaining files to places other tasks can use
copy: {
dist: {
files: [{
expand: true,
dot: true,
cwd: '<%= appConf.app %>',
dest: '<%= appConf.dist %>',
src: [
'*.{ico,png,txt}',
'{,*/}*.html',
'images/{,*/}*.{webp}',
'fonts/*'
]
}, {
expand: true,
cwd: '.tmp/images',
dest: '<%= appConf.dist %>/images',
src: ['generated/*']
}, {
expand: true,
cwd: 'bower_components/font-awesome',
src: 'fonts/*',
dest: '<%= appConf.dist %>'
}]
},
styles: {
files: [
{
expand: true,
cwd: '<%= appConf.app %>/styles',
dest: '.tmp/styles/',
src: '{,*/}*.css'
}
]
}
},
// Run some tasks in parallel to speed up the build process
concurrent: {
server: [
'copy:styles'
],
test: [
'copy:styles'
],
dist: [
'copy:styles',
'svgmin'
]
},
// Add vendor prefixed styles
autoprefixer: {
options: {
browsers: ['last 1 version']
},
dist: {
files: [{
expand: true,
cwd: '.tmp/styles/',
src: '{,*/}*.css',
dest: '.tmp/styles/'
}]
}
},
// The actual grunt server settings
connect: {
options: {
port: 9000,
// Change this to '0.0.0.0' to access the server from outside.
hostname: 'demo.lvh.me',
livereload: 35729
},
livereload: {
options: {
open: true,
middleware: function (connect) {
return [
modRewrite(['^[^\\.]*$ /index.html [L]']),
connect.static('.tmp'),
connect().use(
'/bower_components',
connect.static('./bower_components')
),
connect.static(appConfig.app)
];
}
}
},
test: {
options: {
port: 9001,
middleware: function (connect) {
return [
rewriteRulesSnippet,
connect.static('.tmp'),
connect.static('test'),
connect().use(
'/bower_components',
connect.static('./bower_components')
),
connect.static(appConfig.app)
];
}
}
},
dist: {
options: {
open: true,
base: '<%= appConf.dist %>'
}
}
},
// Make sure code styles are up to par and there are no obvious mistakes
jshint: {
options: {
jshintrc: '.jshintrc',
reporter: require('jshint-stylish')
},
all: {
src: [
'Gruntfile.js',
'<%= appConf.app %>/{,*/}*.js'
]
}
},
// Watches files for changes and runs tasks based on the changed files
watch: {
bower: {
files: ['bower.json'],
tasks: ['wiredep']
},
js: {
files: ['<%= appConf.app %>/{,**/}*.js'],
tasks: ['newer:jshint:all'],
options: {
livereload: '<%= connect.options.livereload %>'
}
},
css: {
files: ['<%= appConf.app %>/styles/{,**/}*.scss'],
tasks: ['sass'],
options: {
livereload: true,
},
},
styles: {
files: [
'<%= appConf.app %>/styles/{,**/}*.css',
'<%= appConf.app %>/../templating/css/style.css'
],
tasks: ['newer:copy:styles', 'autoprefixer']
},
gruntfile: {
files: ['Gruntfile.js']
},
livereload: {
options: {
livereload: '<%= connect.options.livereload %>'
},
files: [
'<%= appConf.app %>/{,**/}*.html',
'.tmp/styles/{,**/}*.css',
'<%= appConf.app %>/images/{,**/}*.{png,jpg,jpeg,gif,webp,svg}'
]
}
},
sass: {
dev: {
options: {
style: 'expanded'
},
files: [
{
expand: true,
cwd: '<%= appConf.app %>/styles',
src: ['*.scss'],
ext: '.css',
dest: '<%= appConf.app %>/styles'
}
]
}
}
});
grunt.loadNpmTasks('grunt-sass');
// Build the development application
grunt.registerTask('serve', 'Compile then start a connect web server', function () {
grunt.task.run([
'clean:server',
'ngconstant:development',
'wiredep',
'sass',
'concurrent:server',
'autoprefixer',
'connect:livereload',
'watch'
]);
});
};

Answer 1

The tutorial assumes that server.js contains your actual server.
If your server is started by grunt serve, just change the start script to run that instead.

Answer 2

this seems quite more logical to me :) So I tested it and deployement was well but the app crashes with this error :
Starting process with command npm start
2016-03-03T17:14:35.928347+00:00 app[web.1]:
2016-03-03T17:14:35.928397+00:00 app[web.1]: > # start /app
2016-03-03T17:14:35.928412+00:00 app[web.1]: > grunt serve
2016-03-03T17:14:35.928413+00:00 app[web.1]:
2016-03-03T17:14:35.951390+00:00 app[web.1]: sh: 1: grunt: not found
2016-03-03T17:14:35.963949+00:00 app[web.1]:
2016-03-03T17:14:35.978885+00:00 app[web.1]: npm ERR! Linux 3.13.0-77-generic
2016-03-03T17:14:35.979392+00:00 app[web.1]: npm ERR! argv "/app/.heroku/node/bin/node" "/app/.heroku/node/bin/npm" "start"
2016-03-03T17:14:35.979644+00:00 app[web.1]: npm ERR! node v4.2.2
2016-03-03T17:14:35.984767+00:00 app[web.1]: npm ERR! npm v2.14.7
2016-03-03T17:14:35.985031+00:00 app[web.1]: npm ERR! file sh
2016-03-03T17:14:35.985243+00:00 app[web.1]: npm ERR! code ELIFECYCLE
2016-03-03T17:14:35.985481+00:00 app[web.1]: npm ERR! errno ENOENT
2016-03-03T17:14:35.985718+00:00 app[web.1]: npm ERR! syscall spawn
2016-03-03T17:14:35.985939+00:00 app[web.1]: npm ERR! # start: grunt serve
2016-03-03T17:14:35.986118+00:00 app[web.1]: npm ERR! spawn ENOENT
2016-03-03T17:14:35.986312+00:00 app[web.1]: npm ERR!
2016-03-03T17:14:35.986492+00:00 app[web.1]: npm ERR! Failed at the # start script 'grunt serve'.