Deploying a Node.js Application

Deploying to Heroku

To deploy your Node.js app you can use Heroku as hosting
From the site: Heroku is a fully managed container-based cloud platform, with integrated data services and a powerful ecosystem, for deploying and running modern apps
Let's get started with installing the Heroku Command Line Interface (CLI)
- Windows
  - Download the installer
- MacOS
```
brew install heroku/brew/heroku
```
- Ubuntu 16+
```
sudo snap install heroku --classic
```

Use the heroku login command to log in to the Heroku CLI:

heroku login
heroku: Press any key to open up the browser to login or q to exit
›   Warning: If browser does not open, visit
›   https://cli-auth.heroku.com/auth/browser/***
heroku: Waiting for login...
Logging in... done
Logged in as me@example.com

Let's create a new node package
```
cd node-example
npm init
```
Next install express
```
npm install express --save
```

For Heroku, it is important to specify the version of node to match your version node --version, edit the package.json to set the engine version.

{
  "name": "node-example",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "dependencies": {
    "express": "^4.17.1"
  },
  "engines": {
    "node": "10.x"
  }
}

Specify the start script in package.json

{
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1",
    "start": "node index.js"
  }
}

Next lets update the index.js to include a basic express app. Note that we are passing the environment variable PORT to our app.

const express = require("express");
const port = process.env.PORT;
const app = express();

app.get("/", (request, response) => {
  response.send("Hello Heroku World!");
});

app.listen(port, () => {
  console.log(`Example app listening on port ${port}`);
});

Build and run your application locally
```
npm install
heroku local
```

After you commit your changes to git, you can deploy your app to Heroku.

git init
git add .
git commit -m "Added a Procfile."
heroku login
Enter your Heroku credentials.
...
heroku create
Creating arcane-lowlands-8408... done, stack is cedar
http://arcane-lowlands-8408.herokuapp.com/ | git@heroku.com:arcane-lowlands-8408.git
Git remote heroku added
git push heroku master
...
-----> Node.js app detected
...
-----> Launching... done
      http://arcane-lowlands-8408.herokuapp.com deployed to Heroku

To open the app in your browser, type heroku open.

Setting up the MongoDB database

For our course and development, we will leverage MongoDB Atlas free cloud-hosted sandbox database. This database tier is not considered suitable for production websites because it has no redundancy, but it is great for development and prototyping.
You will first need to create an account with MongoDB Atlas (this is free, and just requires that you enter basic contact details and acknowledge their terms of service)
After logging in, you'll be taken to the home screen:

Click Build a Cluster button in the Clusters Overview section.
This will open the Create New Cluster screen.
- Select any provider from the Cloud Provider & Region section. Different providers offer different regions.
- Select any region marked "FREE TIER AVAILABLE".
- Click the Create Cluster button (creation of the cluster will take some minutes).
You will return to the Cluster Overview screen.
- Click the Collections button.
This will open the Collections section.
- Click the Create Database button.
This will open the Create Database screen.
- Enter the name for the new database as public.
- Enter the name of the collection as Collection0.
- Click the Create button to create the database.
You will return to the Collection screen with your database created.
- Click the Overview tab to return the cluster overview.
From the Cluster0 Overview screen click the Connect button.
This will open the Connect to Cluster screen.
- Click the Add a Different IP Address button, enter 0.0.0.0/0 for the IP Address and click Add IP Address button.
  - Note: It is a best practice to limit the IP addresses that can connect to your database and other resources. Here we allow a connection from anywhere because we don't know where the request will come from after deployment.
- Enter a username and password and click Create MongoDB User button.
  - Note: Avoid using special characters in your MongoDB user password as mongoose may not parse the connection string properly.
- If you have completed the 2 previous steps, the button Choose a connection method will turn green.
- Click the Choose a connection method button.
This will access the Choose a connection method tab.
- Click the Connect Your Application option.
This will open the Connect screen.
- Click the Short SRV connection string option to copy the connection string.
This will open the connection string URL.
- Choose Copy button to copy the string.
- Save this string somewhere safe.
- Update the password with your users password.
- Replace test with public.
You have now created the database, and have an URL (with username and password) that can be used to access it. This will look something like: mongodb+srv://your_user_name:your_password@cluster0-mbdj7.mongodb.net/public?retryWrites=true
- DO NOT COMMIT THE VALUE TO GIT. Since this contains a secret (the user and password in the connection string), it is best practice to leverage enviroment variables.

Deploying to Heroku​

Setting up the MongoDB database​

Resources​

Deploying to Heroku

Setting up the MongoDB database

Resources