Running NodeJS application on Android

No doubt you will enjoy running NodeJS on your Android device. Thanks to the terminal emulator and Linux environment for Android, the development of web applications on your smartphone will no longer be a problem for you.

Termux

Termux is a free application that can be installed directly from the Google Play store . Requires Android 5.0 or later. No root privileges required.
When you open Termux, you are greeted by the command line interface. It is recommended that you check for updates immediately after installing Termux. Type the following command and press Enter:

$ apt update

Termux comes with minimal basic hardware, so you must install coreutils to fully utilize command line commands such as mv, ls, etc.

$ apt install coreutils

Termux stores data in its own data warehouse, i.e. the $ HOME folder is located inside a private Termux area, like a regular Android application. Removing Termux will cause the loss of this data. If you are going to store important files there, then use termux-setup-storage to ensure that data is stored in external storage (for example, on an SD card).

So, let's create a folder for our application and go to this directory:

Keyboard

At this point, you will most likely feel some problems when working in the console with a standard keyboard. To get around them, I installed a hacker keyboard from Google play . This is a touch keyboard that has everything you need to write code - Esc, Tab and arrow keys.

Nano

To write the code, we need any text editor available in the console. You can install Emacs or Vim, but for simplicity you can use nano. Install it:

$ apt install nano

Create the app.js file and open it in the editor:

$ touch app.js 
$ nano app.js

Let's write some simple NodeJS code to check:

console.log('NodeJS running on Android');

To exit nano, you need to press Ctrl + X, write 'yes' and press Enter.

NodeJS

Now is the time to install NodeJS. It is very easy to do:

$ apt install nodejs

Now we can finally run our script:

$ node app.js

Express

Together with NodeJS, the npm package manager is available to us. Let's use it:

$ npm init
$ npm install express --save
$ nano app.js

Open app.js and write / copy-paste the following code there:

var express = require('express'),
    app = express(),
    port = Number(process.env.PORT || 8080);
app.get('/', function(req, res) {
   res.send('Express is working');
});
app.listen(port, function() {
   console.log('Listening on port ' + port);
});

$ node app.js

This should print to the console the port number on which the server is responding. If you open http: // localhost: 8080 / in a browser, you will see the following text on the page:

Nodemon

To avoid manually restarting the server each time the app.js file changes, we can install nodemon. Nodemon is a utility that will track changes in your code and automatically restart the server.

$ npm install nodemon --save-dev

Now you can start the server using the nodemon command instead of node:

$ nodemon app.js

Git

Even with a hacker keyboard, writing code on the touch screen is not very convenient. Most likely, you write your code in much more convenient places and store it in the repository. Install git:

$ apt install git

Now you can run git commands like git push, git pull, etc. without any errors.

Mongodb

Unfortunately, I did not manage to run the MongoDB server on Android. As an alternative, you can use cloud services such as MongoLab or be content with something like NeDB .

See also:

Building a Node.js application on Android
Termux is the ONE for Android