How to host a RESTful Node.js server with MongoDB Atlas database on Heroku

cpclark360 — Sun, 24 Nov 2019 19:51:42 +0000

Prerequisites

Node.js - Installed
MongoDB Atlas - AWS free tier cluster Account
Text-editor - Visual Studio Code, Atom and etc.
Git - Installed

Dependencies Used

cors version 2.8.5
express version 4.17.1
mongoose version 5.7.12

Assumptions

The RESTful Node.js server with MongoDB database works when running on your localhost.

The MongoDB Connection String, you can find it by:

Sign-in at mongoDB Altas
Locate the cluster you're using for server
Click " CONNECT" > Click " Connect Your Application

Set MongoDB Altas - whitelist to 0.0.0.0/0

To set click 'Network Access' under Security tab > click 'ADD IP ADDRESS'

note

Whitelist - MongoDB Atlas allows client connections to the cluster from entries in the project’s whitelist. You must add an entry to the whitelist to connect the client.CIDR notation 0.0.0.0/0 is used to allow all client connections to the cluster. However, you can add a specific IP address/es.

Go to Heroku dashboard > Select your server App > Settings > Reveal Config Vars

Add ' MONGODB_URL ' as a Config Vars KEY in HEROKU, and add connection string as the VALUE then click 'Add'.
Store Cluster - connection string as a node.js process environment variable called ' MONGODB_URL ' in the main server javascript file.

For Example: server.js

const db = process.env.MONGODB_URL;

const connectDB = async () => {
  try {
    await mongoose.connect(db, {
      useUnifiedTopology: true,
      useNewUrlParser: true
    });
    console.log("MongoDB is Connected...");
  } catch (err) {
    console.error(err.message);
    process.exit(1);
  }
};

To allow inbound requests to the server using CORS

Add FrontEnd site URL where it says "Your FrontEnd Website URL"

For Example:

// cors origin URL - Allow inbound traffic from origin
corsOptions = {
  origin: "Your FrontEnd Website URL",
  optionsSuccessStatus: 200 // some legacy browsers (IE11, various SmartTVs) choke on 204
};
app.use(cors(corsOptions));

note

The code example above is for allowing a single-origin if you want to allow more than one origin refer here

To Deploy select your App then click "Deploy" and choose one of the deployment methods.

Troubleshooting Tips

If you encounter Heroku runtime errors you can view logs below

note

If you are getting errors stating Heroku can't find your modules when trying to deploy, it may be because you are using relative paths for example: const connectDB = require("./config/db");

You will have to use absolute paths because Heroku creates its own FileSystem at deployment.

DEV Community: cpclark360

How to host a RESTful Node.js server with MongoDB Atlas database on Heroku

Prerequisites

Dependencies Used

Assumptions

The MongoDB Connection String, you can find it by:

Set MongoDB Altas - whitelist to 0.0.0.0/0

note

For Example: server.js

For Example:

note

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