How to set up a server with node.js & express and deploy to heroku

Hello world! 😊

This article will show you how to set up node.js server using express. It’s also available in Korean, my native language.

It assumes that you are somewhat familiar with javascript and you have latest version of node and npm installed.

Install express and create a simple “hello world” server

1. Create a directory. I’d recommend something like “server”
2. In the directory run npm init
3. Install express npm install — save express
4. Create index.js file in the same directory, this will be the entry point of your server.
5. In that file, import express module const express = require(“express”)
   *Node does not support ES6 import yet thus we are using CommonJS
6. Declare your app and hook it up with express const app = express()
7. Let’s make it do something. Basic syntax for that goes like this,

app.get("/", (req, res) => {
   res.send({ hello: "world" });
});

8. Make your app listen to requests made to port 3000 by app.listen(3000)

9. Turn your newly created server by running node index.js in your terminal.

10. Go to localhost:3000 to check it out! (pretty easy huh?) At this point, your index.js file should look like this,

const express = require("express");
const app = express();
app.get("/", (req, res) => {
    res.send({ hello: "world" });
});
app.listen(3000);

Deploy your server to Heroku pt.1

Now we have a server, let’s put it out on the internet. We are going to use Heroku as our remote server, so sign up for an account.

1. Heroku assigns port for you. So instead pointing the server to localhost 3000, we will assign heroku port for our app to listen to. Let’s do,
   const PORT = process.env.PORT You can name that const whatever you’d like.
2. Let’s pass that port information into our app by switching toapp.listen(PORT). Now our app will listen to process.env.PORT
3. Before we push the app to Heroku, we have few more things to set up. We need to tell Heroku which version of node and npm we are using for our app. Go to package.json and insert,

"engines":{
    "node": //your node version ,
    "npm": //your npm version

*you can check the versions of those by running -v . eg) npm -v

4. We also need to tell Heroku what command to run to start the server. Go back to package.json , in the“scripts” key, assign “start”: “node index.js”

5. Last thing! We need to make sure that we don’t upload all the modules we have. Create .gitignore file, and inside type node_modules .

Deploy your server to Heroku pt.2

We are now ready to deploy our server to Heroku. We will make use of heroku CLI, so if you haven’t installed it, install it globally. We also need git, so be sure to install that as well!

1. After making sure you have everything installed, initialize a git repository in your server directory. Run git init
2. Login to Heroku in your terminal. Run heroku login
3. Initiate a heroku server by running heroku create. This will generate remote git repo as well.
4. Make sure your repo and heroku repo are connected. Run git remote add heroku YOURHEROKUGITADDRESS (make sure you put your heroku git address)
5. Add & Commit your repo. Not sure how to? Bookmark this page and look for “git add” and “git commit” It should be straight-forward.
6. Finally push it! Run, git push heroku master
7. Hooray! You now have a express server on the web check it out by running heroku open

Hope this helps. Please shoot me any questions if you are stuck — thanks!

Repo link is here!