Run your Node.js application on a headless Raspberry Pi

Run your Node.js application on a headless Raspberry Pi

<strong>How to setup Node.js on a Raspberry Pi and run a node script on boot. How to set up a ... your script. Run node app.js and make sure it doesn't give any errors.</strong>

How to setup Node.js on a Raspberry Pi and run a node script on boot. How to set up a ... your script. Run node app.js and make sure it doesn't give any errors.

Recently I’ve got a little piece of hardware (Raspberry Pi 2 Model B) on my desk. Rather than have it sit on its ass all day, I got a little Node.js application up and running through Nginx.

Get that Raspberry Pi up and running

A headless install doesn’t require any kind of extra hardware (such as screens or keyboard), so everything that you need is the Raspberry Pi itself, a microSD (or SD, depending on your hardware) card and an internet connection (wired or wireless, again depending on your Raspberry).

1. Get the Raspbian Stretch image

Raspbian is the most optimized OS for Raspberries and I use it when I need a minimum and fast setup. Just go the official website and download the latest version of Raspbian Stretch Lite.

2. Burn that image

Insert your card in your PC and burn the Raspbian image on it.

I followed these instructions (Linux/Windows also available) because I prefer using my terminal, but Etcher (a graphical alternative on steroids) is also available on all platforms.

3. Enable headless SSH connections

SSH is not enabled by default in Raspbian, so you will have to do it before you boot the card for the first time.

After the installation, go to boot/ and create a file called ssh (no extension).

touch ssh


4. Boot that Raspberry Pi

Insert the card, the power source, and the network cable. After the green LEDs stop blinking, your Raspberry Pi is good to go!

5. Find that Raspberry Pi

So you have power, network and an OS, no keyboard, no screen. How do you connect to the Raspberry Pi?

In order to SSH into it, you will have to find it in your network first. Supposing that you connected the Raspberry to your home network, you can see all the devices (MAC and IP addresses) in your LAN from the ARP table. Simply run in your terminal (working on all platforms)

arp -a


and you will find your Raspberry Pi right there.

fritz.box (192.168.178.1) on en1 ifscope [ethernet]
raspberrypi.fritz.box (192.168.178.73) on en1 ifscope [ethernet]


In my case, fritz.box is my router and right after is my Raspberry Pi. So from now on, I will connect to it through 192.168.178.73 address.

More about ARP tables and how you should find your devices there.

[

](https://res.cloudinary.com/practicaldev/image/fetch/s--pynt8F0w--/c_limit%2Cf_auto%2Cfl_progressive%2Cq_auto%2Cw_880/https://res.cloudinary.com/practicaldev/image/fetch/s--Qq1LHpN3--/c_fill%2Cf_auto%2Cfl_progressive%2Ch_150%2Cq_auto%2Cw_150/https://thepracticaldev.s3.amazonaws.com/uploads/user/profile_image/20120/f6355e24-68e5-42a1-bf8f-07dcb87e14b5.jpeg) "https://res.cloudinary.com/practicaldev/image/fetch/s--pynt8F0w--/c_limit%2Cf_auto%2Cfl_progressive%2Cq_auto%2Cw_880/https://res.cloudinary.com/practicaldev/image/fetch/s--Qq1LHpN3--/c_fill%2Cf_auto%2Cfl_progressive%2Ch_150%2Cq_auto%2Cw_150/https://thepracticaldev.s3.amazonaws.com/uploads/user/profile_image/20120/f6355e24-68e5-42a1-bf8f-07dcb87e14b5.jpeg)")

](/onmyway133) [

Understanding ARP at the MAC layer

Khoa Pham

#arp#mac#ip

](/onmyway133/understanding-arp-at-the-mac-layer-2a14)

6. Finally SSH into that Raspberry Pi

The default credentials are

username: pi
password: raspberry


SSH into the Raspberry Pi. On Mac or Linux you can just simply run

ssh [email protected]


while on Windows are a few alternatives such as Putty or the default config on Cmder.

Get your Node.js application up and running

You are in! You should get your Node.js application up, so the following steps are run through SSH, on your Raspberry Pi.

1. Install Node.js on Raspbian

There are a lot of ways to install Node.js on a Linux machine, but I always follow NodeSource’s instructions, being the safest way I ever did.

For Node.js v11.x I ran

sudo apt-get update
curl -sL https://deb.nodesource.com/setup_11.x | bash -
sudo apt-get install -y nodejs


Anyways, curl -sL [https://deb.nodesource.com/setup_11.x](https://deb.nodesource.com/setup_11.x "https://deb.nodesource.com/setup_11.x") | bash - will provide more instructions if you need more tools or add-ons.

Check if Node.js and npm are installed properly.

$ node -v
v11.10.0

$ npm -v
6.7.0


For other versions or troubleshooting take a look to NodeSource’s comprehensive docs. Raspbian is a Debian based OS, so look for Debian instructions.

nodesource / distributions

NodeSource Node.js Binary Distributions

NodeSource Node.js Binary Distributions

This repository contains documentation for using the NodeSource Node.js Binary Distributions via .rpm, .deb and Snap packages as well as their setup and support scripts.

If you are looking for NodeSource’s Enterprise-grade Node.js platform, N|Solid, please visit https://downloads.nodesource.com/

Please file an issue if you are experiencing a problem or would like to discuss something related to the distributions.

Pull requests are encouraged if you have changes you believe would improve the setup process or increase compatibility across Linux distributions.

Table of Contents Debian and Ubuntu based distributions

Available architectures:

NodeSource will continue to maintain the following architectures and may add additional ones in the future.

View on GitHub](https://github.com/nodesource/distributions) "https://github.com/nodesource/distributions)")

If you choose to write or paste the code, quickly install vim, it will make our lives easier and later I will walk you through, don’t worry.

sudo apt-get update
sudo apt-get install vim -y


2. Get your Node.js app

Write, copy-paste or clone the Node.js application. For testing purposes, I created app.js file.

cd ~
vim app.js


I pasted the following boilerplate

const http = require('http');

const HOSTNAME = '127.0.0.1';
const PORT = 3000;

const server = http.createServer((req, res) => {
  res.statusCode = 200;
  res.setHeader('Content-Type', 'text/plain');
  res.end('Hello dev.to!\n');
});

server.listen(PORT, HOSTNAME, () => {
  console.log(`Server running at ${HOSTNAME} on port ${PORT}.`);
});


If vim is too overwhelming you can try to use other ways as nano. But just to be sure, this is a really quick follow-up:

  1. Open (or create) the file with vim app.js.

  2. Now, vim is in the normal mode and it’s waiting for your command. Press i to go in the insert mode, this will allow you write code.

  3. Type or paste your code now, exactly how you’d do it in your editor.

  4. If you’re done writing, press esc so you go back to the normal mode so you can command vim to save and exit.

  5. Usually, vim commands start with :. Gently press : followed by w for writing and q for quitting. You can actually see the commands that you’re typing on the bottom of your terminal. Press enter to acknowledge the commands.

  6. Taa-daaaaa. app.js is saved.

If you want to do more crazy tricks with vim, follow-up this beginner guide and you will see that vim is not that bad.

[

](https://res.cloudinary.com/practicaldev/image/fetch/s--DVPUhCju--/c_limit%2Cf_auto%2Cfl_progressive%2Cq_auto%2Cw_880/https://res.cloudinary.com/practicaldev/image/fetch/s--L3sgMMqB--/c_fill%2Cf_auto%2Cfl_progressive%2Ch_150%2Cq_auto%2Cw_150/https://thepracticaldev.s3.amazonaws.com/uploads/user/profile_image/50687/03827052-2382-44b8-adbb-2315f8d649ee.png) "https://res.cloudinary.com/practicaldev/image/fetch/s--DVPUhCju--/c_limit%2Cf_auto%2Cfl_progressive%2Cq_auto%2Cw_880/https://res.cloudinary.com/practicaldev/image/fetch/s--L3sgMMqB--/c_fill%2Cf_auto%2Cfl_progressive%2Ch_150%2Cq_auto%2Cw_150/https://thepracticaldev.s3.amazonaws.com/uploads/user/profile_image/50687/03827052-2382-44b8-adbb-2315f8d649ee.png)")

](/hamza) [

Vim for starters - the minimum you need to know

Hamza Tamenaoul

#vim#linux#terminal#beginners

](/hamza/vim-for-starters---the-minimum-you-need-to-know-3ob)

3. Finally run the Node.js application

Run

$ node app
Server running at 127.0.0.1 on port 3000.


and your Node.js app will run on localhost:3000/.

Because none of the ports are opened by default, you can test the app only from your Raspberry Pi. Open a new tab of the SSH connection and run

curl localhost:3000


and you should get

Hello dev.to!


4. Install PM2

Of course that you want your application daemonized (in background) and of course that you want your application to start when the system is restarting. PM2 will provide all of this.

Stop your Node.js application (ctrl + C) and proceed to installation.

We will use npm to install PM2 globally -g.

sudo npm install -g pm2


Start the application with PM2

To start app.js with PM2 run

pm2 start app.js


and you should see

[PM2] Starting /home/pi/app.js in fork_mode (1 instance)
[PM2] Done.
┌──────────┬────┬─────────┬──────┬─────┬────────┬─────────┬────────┬─────┬───────────┬──────┬──────────┐
│ App name │ id │ version │ mode │ pid │ status │ restart │ uptime │ cpu │ mem       │ user │ watching │
├──────────┼────┼─────────┼──────┼─────┼────────┼─────────┼────────┼─────┼───────────┼──────┼──────────┤
│ app      │ 0  │ N/A     │ fork │ 738 │ online │ 0       │ 0s     │ 0%  │ 21.8 MB   │ pi   │ disabled │
└──────────┴────┴─────────┴──────┴─────┴────────┴─────────┴────────┴─────┴───────────┴──────┴──────────┘


Now app.js is daemonized running. You can test it as we did before with curl localhost:3000.

Bonus: if the app crashes, PM2 will restart it.

PM2 startup

The pm2 startup command will generate a script that will lunch PM2 on boot together with the applications that you configure to start.

pm2 startup systemd


will generate

[PM2] Init System found: systemd
[PM2] To setup the Startup Script, copy/paste the following command:
sudo env PATH=$PATH:/usr/bin /usr/lib/node_modules/pm2/bin/pm2 startup systemd -u pi --hp /home/pi


Copy the generated command and run it.

sudo env PATH=$PATH:/usr/bin /usr/lib/node_modules/pm2/bin/pm2 startup systemd -u pi --hp /home/p


This created a system unit that will start PM2 on boot. When the system will boot PM2 will resurrect from a dump file that is not created yet. To create it run

pm2 save


This will save the current state of PM2 (with app.js running) in a dump file that will be used when resurrecting PM2.

That’s it! Your application is currently running and in case of a restart, it will start when the system boots.

PM2 daemon

You will be able to check anytime the status of your application with pm2 listpm2 status or pm2 show.

$ pm2 list
┌──────────┬────┬─────────┬──────┬─────┬────────┬─────────┬────────┬──────┬───────────┬──────┬──────────┐
│ App name │ id │ version │ mode │ pid │ status │ restart │ uptime │ cpu  │ mem       │ user │ watching │
├──────────┼────┼─────────┼──────┼─────┼────────┼─────────┼────────┼──────┼───────────┼──────┼──────────┤
│ app      │ 0  │ N/A     │ fork │ 451 │ online │ 0       │ 96m    │ 0.2% │ 31.8 MB   │ pi   │ disabled │
└──────────┴────┴─────────┴──────┴─────┴────────┴─────────┴────────┴──────┴───────────┴──────┴──────────┘

$ pm2 show app
┌───────────────────┬──────────────────────────────────┐
│ status            │ online                           │
│ name              │ app                              │
│ version           │ N/A                              │
│ restarts          │ 0                                │
│ uptime            │ 97m                              │
│ script path       │ /home/pi/app.js                  │
│ script args       │ N/A                              │
│ error log path    │ /home/pi/.pm2/logs/app-error.log │
│ out log path      │ /home/pi/.pm2/logs/app-out.log   │
│ pid path          │ /home/pi/.pm2/pids/app-0.pid     │
│ interpreter       │ node                             │
│ interpreter args  │ N/A                              │
│ script id         │ 0                                │
│ exec cwd          │ /home/pi                         │
│ exec mode         │ fork_mode                        │
│ node.js version   │ 11.10.0                          │
│ node env          │ N/A                              │
│ watch & reload    │ ✘                                │
│ unstable restarts │ 0                                │
│ created at        │ 2019-02-17T14:14:35.027Z         │
└───────────────────┴──────────────────────────────────┘


There is a lot of greatness within PM2 that you can use, read more about logs and processes below.

[

](https://res.cloudinary.com/practicaldev/image/fetch/s--D2lgk2QQ--/c_limit%2Cf_auto%2Cfl_progressive%2Cq_auto%2Cw_880/https://res.cloudinary.com/practicaldev/image/fetch/s--Cvne3mtI--/c_fill%2Cf_auto%2Cfl_progressive%2Ch_150%2Cq_auto%2Cw_150/https://thepracticaldev.s3.amazonaws.com/uploads/user/profile_image/23591/6b3970ab-71b1-4cdb-8413-57ac3c24174b.jpg) "https://res.cloudinary.com/practicaldev/image/fetch/s--D2lgk2QQ--/c_limit%2Cf_auto%2Cfl_progressive%2Cq_auto%2Cw_880/https://res.cloudinary.com/practicaldev/image/fetch/s--Cvne3mtI--/c_fill%2Cf_auto%2Cfl_progressive%2Ch_150%2Cq_auto%2Cw_150/https://thepracticaldev.s3.amazonaws.com/uploads/user/profile_image/23591/6b3970ab-71b1-4cdb-8413-57ac3c24174b.jpg)")

](/nickparsons) [

Running PM2 & Node.js in Production Environments

Nick Parsons

#pm2#node#processmanagement

](/nickparsons/running-pm2--nodejs-in-production-environments-23i5)

Make use of a Reverse Proxy

As I mentioned before, none of the ports on your devices are publicly open yet, so you cannot access your Raspberry Pi from the outer world. There are a ton of reason why you should or shouldn’t use a reverse proxy for your Node.js application. Because of scalability and security reasons (and also is really simple to setup and manage), I will use Nginx as a Reverse Proxy Server for this application.

0. Don’t use a Reverse Proxy :(

If you plan to use a Reverse Proxy don’t follow this step otherwise you will mess up the ports (like having 80 and 3000 opened at the same time).

An uncomplicated way to go without a Reverse Proxy is to use [ufw](https://help.ubuntu.com/community/UFW "ufw") to allow some of the ports to allow incoming traffic. But note that this might be a big security flaw.

Install it by running

sudo apt-get install ufw


A quick sudo ufw status verbose will show us that ufw is currently inactive. Before you enable it, you should allow all the SSH traffic to your device, so the connection is not disturbed.

$ sudo ufw allow ssh
Rules updated
Rules updated (v6)


Now you can enable it.

sudo ufw enable


Another quick sudo ufw status verbose will show that all incoming SSH traffic is allowed. All the outgoing traffic is allowed, so don’t worry about it. Now just go on and allow connections on 3000, the port of your application.

sudo ufw allow 3000


Now you can access from the outside of the world! You can type your device’s address followed by the port in your browser.

1. Install NGINX

I used Nginx as a Reverse Proxy Server to redirect all the traffic to/from port 80 to my application, on port 3000. Install Nginx running

sudo apt update
sudo apt install nginx


After the installation, Nginx will be running right away. The default port opened is 80 and you can test it by browsing to your Raspberry’s address.

2. Configure the Reverse Proxy Server

There is a lot to say about Reverse Proxies, but we will stick to basics now.

You will edit the default configuration (that serves the HTML page that you saw in your browser) to make the proper redirects.

sudo vim /etc/nginx/sites-available/default


If you are not familiar to Nginx, /etc/nginx/sites-available/default is a long, confusing file. I will get rid of all the comments so you can see it better.

server {
        listen 80 default_server;
        listen [::]:80 default_server;

        root /var/www/html;

        index index.html index.htm index.nginx-debian.html;

        server_name _;

        location / {
            # First attempt to serve request as file, then
            # as directory, then fall back to displaying a 404.
            try_files $uri $uri/ =404;
            # proxy_pass http://localhost:8080;
            # proxy_http_version 1.1;
            # proxy_set_header Upgrade $http_upgrade;
            # proxy_set_header Connection 'upgrade';
            # proxy_set_header Host $host;
            # proxy_cache_bypass $http_upgrade;
        }
}


You will need the basic configuration, therefore leave it be. You will make changes to location / { block.

Uncomment the commented section inside that block, change the port to 3000, get rid of the first lines and that exact configuration is a Reverse Proxy (or just copy the following code).

server {
        listen 80 default_server;
        listen [::]:80 default_server;

        root /var/www/html;

        index index.html index.htm index.nginx-debian.html;

        server_name _;

        location / {
            proxy_pass http://localhost:3000;
            proxy_http_version 1.1;
            proxy_set_header Upgrade $http_upgrade;
            proxy_set_header Connection 'upgrade';
            proxy_set_header Host $host;
            proxy_cache_bypass $http_upgrade;
        }
}


Check for syntax errors in Nginx with

sudo nginx -t


and finally restart the Nginx server.

sudo systemctl restart nginx


Test it out by browsing to your Raspberry’s address.

Done! All the requests to your Raspberry’s address will be redirected to your Node.js application.

Note that this is a basic configuration of Nginx, you can discover more about other features here.

[

](https://res.cloudinary.com/practicaldev/image/fetch/s--cxPIt7H1--/c_limit%2Cf_auto%2Cfl_progressive%2Cq_auto%2Cw_880/https://res.cloudinary.com/practicaldev/image/fetch/s--nr6UezBJ--/c_fill%2Cf_auto%2Cfl_progressive%2Ch_150%2Cq_auto%2Cw_150/https://thepracticaldev.s3.amazonaws.com/uploads/user/profile_image/22851/c1e857d6-6ad3-46af-88d0-933d3078611c.jpg) "https://res.cloudinary.com/practicaldev/image/fetch/s--cxPIt7H1--/c_limit%2Cf_auto%2Cfl_progressive%2Cq_auto%2Cw_880/https://res.cloudinary.com/practicaldev/image/fetch/s--nr6UezBJ--/c_fill%2Cf_auto%2Cfl_progressive%2Ch_150%2Cq_auto%2Cw_150/https://thepracticaldev.s3.amazonaws.com/uploads/user/profile_image/22851/c1e857d6-6ad3-46af-88d0-933d3078611c.jpg)")

](/mozartted) [

Understanding nginx (proxying, reverse proxying, load balancing)

Osita Chibuike

#servers#programming#devops

](/legobox/understanding-nginx-proxying-reverse-proxying-load-balancing-1pjd)

Finale

Now you are done! So you got a Node.js application running (daemonized) on a headless Raspberry Pi that deals with requests through an Nginx Reverse Proxy Server.

Hopefully, this was a comprehensive enough guide, but I am open to discussions and questions below. Let us know what you’ve experienced or what other alternatives you found on the way.

Learn More

☞ The Complete Node.js Developer Course (2nd Edition)

☞ Learn and Understand NodeJS

☞ Node JS: Advanced Concepts

☞ GraphQL: Learning GraphQL with Node.Js

☞ Angular (Angular 2+) & NodeJS - The MEAN Stack Guide

☞ Beginner Full Stack Web Development: HTML, CSS, React & Node

☞ Node with React: Fullstack Web Development

☞ MERN Stack Front To Back: Full Stack React, Redux & Node.js

How to Use Express.js, Node.js and MongoDB.js

How to Use Express.js, Node.js and MongoDB.js

In this post, I will show you how to use Express.js, Node.js and MongoDB.js. We will be creating a very simple Node application, that will allow users to input data that they want to store in a MongoDB database. It will also show all items that have been entered into the database.

In this post, I will show you how to use Express.js, Node.js and MongoDB.js. We will be creating a very simple Node application, that will allow users to input data that they want to store in a MongoDB database. It will also show all items that have been entered into the database.

Creating a Node Application

To get started I would recommend creating a new database that will contain our application. For this demo I am creating a directory called node-demo. After creating the directory you will need to change into that directory.

mkdir node-demo
cd node-demo

Once we are in the directory we will need to create an application and we can do this by running the command
npm init

This will ask you a series of questions. Here are the answers I gave to the prompts.

The first step is to create a file that will contain our code for our Node.js server.

touch app.js

In our app.js we are going to add the following code to build a very simple Node.js Application.

var express = require("express");
var app = express();
var port = 3000;
 
app.get("/", (req, res) => {
&nbsp;&nbsp;res.send("Hello World");
});
 
app.listen(port, () => {
  console.log("Server listening on port " + port);
});

What the code does is require the express.js application. It then creates app by calling express. We define our port to be 3000.

The app.use line will listen to requests from the browser and will return the text “Hello World” back to the browser.

The last line actually starts the server and tells it to listen on port 3000.

Installing Express

Our app.js required the Express.js module. We need to install express in order for this to work properly. Go to your terminal and enter this command.

npm install express --save

This command will install the express module into our package.json. The module is installed as a dependency in our package.json as shown below.

To test our application you can go to the terminal and enter the command

node app.js

Open up a browser and navigate to the url http://localhost:3000

You will see the following in your browser

Creating Website to Save Data to MongoDB Database

Instead of showing the text “Hello World” when people view your application, what we want to do is to show a place for user to save data to the database.

We are going to allow users to enter a first name and a last name that we will be saving in the database.

To do this we will need to create a basic HTML file. In your terminal enter the following command to create an index.html file.

touch index.html

In our index.html file we will be creating an input filed where users can input data that they want to have stored in the database. We will also need a button for users to click on that will add the data to the database.

Here is what our index.html file looks like.

<!DOCTYPE html>
<html>
  <head>
    <title>Intro to Node and MongoDB<title>
  <head>

  <body>
    <h1>Into to Node and MongoDB<&#47;h1>
    <form method="post" action="/addname">
      <label>Enter Your Name<&#47;label><br>
      <input type="text" name="firstName" placeholder="Enter first name..." required>
      <input type="text" name="lastName" placeholder="Enter last name..." required>
      <input type="submit" value="Add Name">
    </form>
  <body>
<html>

If you are familiar with HTML, you will not find anything unusual in our code for our index.html file. We are creating a form where users can input their first name and last name and then click an “Add Name” button.

The form will do a post call to the /addname endpoint. We will be talking about endpoints and post later in this tutorial.

Displaying our Website to Users

We were previously displaying the text “Hello World” to users when they visited our website. Now we want to display our html file that we created. To do this we will need to change the app.use line our our app.js file.

We will be using the sendFile command to show the index.html file. We will need to tell the server exactly where to find the index.html file. We can do that by using a node global call __dirname. The __dirname will provide the current directly where the command was run. We will then append the path to our index.html file.

The app.use lines will need to be changed to
app.use("/", (req, res) => {   res.sendFile(__dirname + "/index.html"); });

Once you have saved your app.js file, we can test it by going to terminal and running node app.js

Open your browser and navigate to “http://localhost:3000”. You will see the following

Connecting to the Database

Now we need to add our database to the application. We will be connecting to a MongoDB database. I am assuming that you already have MongoDB installed and running on your computer.

To connect to the MongoDB database we are going to use a module called Mongoose. We will need to install mongoose module just like we did with express. Go to your terminal and enter the following command.
npm install mongoose --save

This will install the mongoose model and add it as a dependency in our package.json.

Connecting to the Database

Now that we have the mongoose module installed, we need to connect to the database in our app.js file. MongoDB, by default, runs on port 27017. You connect to the database by telling it the location of the database and the name of the database.

In our app.js file after the line for the port and before the app.use line, enter the following two lines to get access to mongoose and to connect to the database. For the database, I am going to use “node-demo”.

var mongoose = require("mongoose"); mongoose.Promise = global.Promise; mongoose.connect("mongodb://localhost:27017/node-demo");

Creating a Database Schema

Once the user enters data in the input field and clicks the add button, we want the contents of the input field to be stored in the database. In order to know the format of the data in the database, we need to have a Schema.

For this tutorial, we will need a very simple Schema that has only two fields. I am going to call the field firstName and lastName. The data stored in both fields will be a String.

After connecting to the database in our app.js we need to define our Schema. Here are the lines you need to add to the app.js.
var nameSchema = new mongoose.Schema({   firstName: String,   lastNameName: String });

Once we have built our Schema, we need to create a model from it. I am going to call my model “DataInput”. Here is the line you will add next to create our mode.
var User = mongoose.model("User", nameSchema);

Creating RESTful API

Now that we have a connection to our database, we need to create the mechanism by which data will be added to the database. This is done through our REST API. We will need to create an endpoint that will be used to send data to our server. Once the server receives this data then it will store the data in the database.

An endpoint is a route that our server will be listening to to get data from the browser. We already have one route that we have created already in the application and that is the route that is listening at the endpoint “/” which is the homepage of our application.

HTTP Verbs in a REST API

The communication between the client(the browser) and the server is done through an HTTP verb. The most common HTTP verbs are
GET, PUT, POST, and DELETE.

The following table explains what each HTTP verb does.

HTTP Verb Operation
GET Read
POST Create
PUT Update
DELETE Delete

As you can see from these verbs, they form the basis of CRUD operations that I talked about previously.

Building a CRUD endpoint

If you remember, the form in our index.html file used a post method to call this endpoint. We will now create this endpoint.

In our previous endpoint we used a “GET” http verb to display the index.html file. We are going to do something very similar but instead of using “GET”, we are going to use “POST”. To get started this is what the framework of our endpoint will look like.

app.post("/addname", (req, res) => {
 
});
Express Middleware

To fill out the contents of our endpoint, we want to store the firstName and lastName entered by the user into the database. The values for firstName and lastName are in the body of the request that we send to the server. We want to capture that data, convert it to JSON and store it into the database.

Express.js version 4 removed all middleware. To parse the data in the body we will need to add middleware into our application to provide this functionality. We will be using the body-parser module. We need to install it, so in your terminal window enter the following command.

npm install body-parser --save

Once it is installed, we will need to require this module and configure it. The configuration will allow us to pass the data for firstName and lastName in the body to the server. It can also convert that data into JSON format. This will be handy because we can take this formatted data and save it directly into our database.

To add the body-parser middleware to our application and configure it, we can add the following lines directly after the line that sets our port.

var bodyParser = require('body-parser');
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: true }));
Saving data to database

Mongoose provides a save function that will take a JSON object and store it in the database. Our body-parser middleware, will convert the user’s input into the JSON format for us.

To save the data into the database, we need to create a new instance of our model that we created early. We will pass into this instance the user’s input. Once we have it then we just need to enter the command “save”.

Mongoose will return a promise on a save to the database. A promise is what is returned when the save to the database completes. This save will either finish successfully or it will fail. A promise provides two methods that will handle both of these scenarios.

If this save to the database was successful it will return to the .then segment of the promise. In this case we want to send text back the user to let them know the data was saved to the database.

If it fails it will return to the .catch segment of the promise. In this case, we want to send text back to the user telling them the data was not saved to the database. It is best practice to also change the statusCode that is returned from the default 200 to a 400. A 400 statusCode signifies that the operation failed.

Now putting all of this together here is what our final endpoint will look like.

app.post("/addname", (req, res) => {
  var myData = new User(req.body);
  myData.save()
    .then(item => {
      res.send("item saved to database");
    })
    .catch(err => {
      res.status(400).send("unable to save to database");
    });
});
Testing our code

Save your code. Go to your terminal and enter the command node app.js to start our server. Open up your browser and navigate to the URL “http://localhost:3000”. You will see our index.html file displayed to you.

Make sure you have mongo running.

Enter your first name and last name in the input fields and then click the “Add Name” button. You should get back text that says the name has been saved to the database like below.

Access to Code

The final version of the code is available in my Github repo. To access the code click here. Thank you for reading !

Node.js for Beginners - Learn Node.js from Scratch (Step by Step)

Node.js for Beginners - Learn Node.js from Scratch (Step by Step)

Node.js for Beginners - Learn Node.js from Scratch (Step by Step) - Learn the basics of Node.js. This Node.js tutorial will guide you step by step so that you will learn basics and theory of every part. Learn to use Node.js like a professional. You’ll learn: Basic Of Node, Modules, NPM In Node, Event, Email, Uploading File, Advance Of Node.

Node.js for Beginners

Learn Node.js from Scratch (Step by Step)

Welcome to my course "Node.js for Beginners - Learn Node.js from Scratch". This course will guide you step by step so that you will learn basics and theory of every part. This course contain hands on example so that you can understand coding in Node.js better. If you have no previous knowledge or experience in Node.js, you will like that the course begins with Node.js basics. otherwise if you have few experience in programming in Node.js, this course can help you learn some new information . This course contain hands on practical examples without neglecting theory and basics. Learn to use Node.js like a professional. This comprehensive course will allow to work on the real world as an expert!
What you’ll learn:

  • Basic Of Node
  • Modules
  • NPM In Node
  • Event
  • Email
  • Uploading File
  • Advance Of Node

Top 7 Most Popular Node.js Frameworks You Should Know

Top 7 Most Popular Node.js Frameworks You Should Know

Node.js is an open-source, cross-platform, runtime environment that allows developers to run JavaScript outside of a browser. In this post, you'll see top 7 of the most popular Node frameworks at this point in time (ranked from high to low by GitHub stars).

Node.js is an open-source, cross-platform, runtime environment that allows developers to run JavaScript outside of a browser.

One of the main advantages of Node is that it enables developers to use JavaScript on both the front-end and the back-end of an application. This not only makes the source code of any app cleaner and more consistent, but it significantly speeds up app development too, as developers only need to use one language.

Node is fast, scalable, and easy to get started with. Its default package manager is npm, which means it also sports the largest ecosystem of open-source libraries. Node is used by companies such as NASA, Uber, Netflix, and Walmart.

But Node doesn't come alone. It comes with a plethora of frameworks. A Node framework can be pictured as the external scaffolding that you can build your app in. These frameworks are built on top of Node and extend the technology's functionality, mostly by making apps easier to prototype and develop, while also making them faster and more scalable.

Below are 7of the most popular Node frameworks at this point in time (ranked from high to low by GitHub stars).

Express

With over 43,000 GitHub stars, Express is the most popular Node framework. It brands itself as a fast, unopinionated, and minimalist framework. Express acts as middleware: it helps set up and configure routes to send and receive requests between the front-end and the database of an app.

Express provides lightweight, powerful tools for HTTP servers. It's a great framework for single-page apps, websites, hybrids, or public HTTP APIs. It supports over fourteen different template engines, so developers aren't forced into any specific ORM.

Meteor

Meteor is a full-stack JavaScript platform. It allows developers to build real-time web apps, i.e. apps where code changes are pushed to all browsers and devices in real-time. Additionally, servers send data over the wire, instead of HTML. The client renders the data.

The project has over 41,000 GitHub stars and is built to power large projects. Meteor is used by companies such as Mazda, Honeywell, Qualcomm, and IKEA. It has excellent documentation and a strong community behind it.

Koa

Koa is built by the same team that built Express. It uses ES6 methods that allow developers to work without callbacks. Developers also have more control over error-handling. Koa has no middleware within its core, which means that developers have more control over configuration, but which means that traditional Node middleware (e.g. req, res, next) won't work with Koa.

Koa already has over 26,000 GitHub stars. The Express developers built Koa because they wanted a lighter framework that was more expressive and more robust than Express. You can find out more about the differences between Koa and Express here.

Sails

Sails is a real-time, MVC framework for Node that's built on Express. It supports auto-generated REST APIs and comes with an easy WebSocket integration.

The project has over 20,000 stars on GitHub and is compatible with almost all databases (MySQL, MongoDB, PostgreSQL, Redis). It's also compatible with most front-end technologies (Angular, iOS, Android, React, and even Windows Phone).

Nest

Nest has over 15,000 GitHub stars. It uses progressive JavaScript and is built with TypeScript, which means it comes with strong typing. It combines elements of object-oriented programming, functional programming, and functional reactive programming.

Nest is packaged in such a way it serves as a complete development kit for writing enterprise-level apps. The framework uses Express, but is compatible with a wide range of other libraries.

LoopBack

LoopBack is a framework that allows developers to quickly create REST APIs. It has an easy-to-use CLI wizard and allows developers to create models either on their schema or dynamically. It also has a built-in API explorer.

LoopBack has over 12,000 GitHub stars and is used by companies such as GoDaddy, Symantec, and the Bank of America. It's compatible with many REST services and a wide variety of databases (MongoDB, Oracle, MySQL, PostgreSQL).

Hapi

Similar to Express, hapi serves data by intermediating between server-side and client-side. As such, it's can serve as a substitute for Express. Hapi allows developers to focus on writing reusable app logic in a modular and prescriptive fashion.

The project has over 11,000 GitHub stars. It has built-in support for input validation, caching, authentication, and more. Hapi was originally developed to handle all of Walmart's mobile traffic during Black Friday.