Tutorial: using a NodeJS hosting - heroku

Set up

In this step you will install the Heroku Command Line Interface (CLI), formerly known as the Heroku Toolbelt. You will use the CLI to manage and scale your applications, to provision add-ons, to view the logs of your application as it runs on Heroku, as well as to help run your application locally.

Download the Heroku CLI for...

Once installed, you can use the heroku command from your command shell.
Log in using the email address and password you used when creating your Heroku account:

 heroku login
Enter your Heroku credentials.
Email: zeke@example.com
Password:
...

Authenticating is required to allow both the heroku and git commands to operate.

If you’re behind a firewall that requires use of a proxy to connect with external HTTP/HTTPS services, you can set the HTTP_PROXY or HTTPS_PROXY environment variables in your local development environment before running the heroku command.

Before you continue, check that you have the prerequisites installed properly. Type each command below and make sure it displays the version you have installed. (Your versions might be different from the example.) If no version is returned, go back to the introduction of this tutorial and install the prerequisites.
All of the following local setup will be required to complete the “Declare app dependencies” and subsequent steps.
This tutorial will work for any version of Node greater than 4 or so - check that it’s there:

 node -v
v5.9.1

npm is installed with Node, so check that it’s there. If you don’t have it, install a more recent version of Node:

 npm -v
3.7.3

Now check that you have git installed. If not, install it and test again.

 git --version
git version 2.2.1

 

Prepare the app

In this step, you will prepare a simple application that can be deployed.
To clone the sample application so that you have a local version of the code that you can then deploy to Heroku, execute the following commands in your local command shell or terminal:

 git clone https://github.com/heroku/node-js-getting-started.git

 cd node-js-getting-started

You now have a functioning git repository that contains a simple application as well as a package.json file, which is used by Node’s dependency manager.

Deploy the app

In this step you will deploy the app to Heroku.
Create an app on Heroku, which prepares Heroku to receive your source code.

 heroku create
Creating sharp-rain-871... done, stack is cedar-14
http://sharp-rain-871.herokuapp.com/ | https://git.heroku.com/sharp-rain-871.git
Git remote heroku added

When you create an app, a git remote (called heroku) is also created and associated with your local git repository.
Heroku generates a random name (in this case sharp-rain-871) for your app, or you can pass a parameter to specify your own app name.
Now deploy your code:

 git push heroku master
Counting objects: 343, done.
Delta compression using up to 4 threads.
Compressing objects: 100% (224/224), done.
Writing objects: 100% (250/250), 238.01 KiB, done.
Total 250 (delta 63), reused 0 (delta 0)
remote: Compressing source files... done.
remote: Building source:
remote:
remote: -----> Node.js app detected
remote:
remote: -----> Creating runtime environment
remote:
remote:        NPM_CONFIG_LOGLEVEL=error
remote:        NPM_CONFIG_PRODUCTION=true
remote:        NODE_MODULES_CACHE=true
remote:
remote: -----> Installing binaries
remote:        engines.node (package.json):  5.9.1
remote:        engines.npm (package.json):   unspecified (use default)
remote:
remote:        Downloading and installing node 5.9.1...
remote:        Using default npm version: 2.7.4
       ....
remote: -----> Build succeeded!
remote:        ├── ejs@2.4.1
remote:        └── express@4.13.3
remote:
remote: -----> Discovering process types
remote:        Procfile declares types -> web
remote:
remote: -----> Compressing... done, 9.4MB
remote: -----> Launching... done, v8
remote:        http://sharp-rain-871.herokuapp.com deployed to Heroku
To https://git.heroku.com/nameless-savannah-4829.git
 * [new branch]      master -> master

The application is now deployed. Ensure that at least one instance of the app is running:

 heroku ps:scale web=1

Now visit the app at the URL generated by its app name. As a handy shortcut, you can open the website as follows:

 heroku open 

Scale the app

Right now, your app is running on a single web dyno. Think of a dyno as a lightweight container that runs the command specified in the Procfile.
You can check how many dynos are running using the ps command:

 heroku ps
=== web (Free): `node index.js`
web.1: up 2014/04/25 16:26:38 (~ 1s ago)

By default, your app is deployed on a free dyno. Free dynos will sleep after a half hour of inactivity (if they don’t receive any traffic). This causes a delay of a few seconds for the first request upon waking. Subsequent requests will perform normally. Free dynos also consume from a monthly, account-level quota of free dyno hours - as long as the quota is not exhausted, all free apps can continue to run.
To avoid dyno sleeping, you can upgrade to a hobby or professional dyno type as described in the Dyno Types article. For example, if you migrate your app to a professional dyno, you can easily scale it by running a command telling Heroku to execute a specific number of dynos, each running your web process type.
Scaling an application on Heroku is equivalent to changing the number of dynos that are running. Scale the number of web dynos to zero:

 heroku ps:scale web=0

Access the app again by hitting refresh on the web tab, or heroku open to open it in a web tab. You will get an error message because you no longer have any web dynos available to serve requests.
Scale it up again:

 heroku ps:scale web=1

For abuse prevention, scaling a non-free application to more than one dyno requires account verification.

Run the app locally

Now start your application locally using the heroku local command, which was installed as part of the Heroku CLI:

 heroku local web
[OKAY] Loaded ENV .env File as KEY=VALUE Format
1:23:15 PM web.1 |  Node app is running on port 5000

Just like Heroku, heroku local examines the Procfile to determine what to run.
Open http://localhost:5000 with your web browser. You should see your app running locally.
To stop the app from running locally, in the CLI, press Ctrl+C to exit.

Push local changes

In this step you’ll learn how to propagate a local change to the application through to Heroku. As an example, you’ll modify the application to add an additional dependency and the code to use it.
Begin by adding a dependency for cool-ascii-faces in package.json. Run the following command to do this:

 npm install --save --save-exact cool-ascii-faces
cool-ascii-faces@1.3.3 node_modules/cool-ascii-faces
└── stream-spigot@3.0.5 (xtend@4.0.1, readable-stream@1.1.13)

Modify index.js so that it requires this module at the start. Also add a new route (/cool) that uses it. Your final code should look like this:

var cool = require('cool-ascii-faces');
var express = require('express');
var app = express();

app.set('port', (process.env.PORT || 5000));

app.use(express.static(__dirname + '/public'));

// views is directory for all template files
app.set('views', __dirname + '/views');
app.set('view engine', 'ejs');

app.get('/', function(request, response) {
  response.render('pages/index')
});

app.get('/cool', function(request, response) {
  response.send(cool());
});

app.listen(app.get('port'), function() {
  console.log('Node app is running on port', app.get('port'));
});

Now test locally:

 npm install

 heroku local

Visiting your application at http://localhost:5000/cool, you should see cute faces displayed on each refresh: ( ⚆ _ ⚆ ).
Now deploy. Almost every deploy to Heroku follows this same pattern. First, add the modified files to the local git repository:

 git add .

Now commit the changes to the repository:

 git commit -m "Demo"

Now deploy, just as you did previously:

 git push heroku master

Finally, check that everything is working:

 heroku open cool

You should see another face.