How To Install Node.js on Debian 8

Introduction #

Node.js is a JavaScript platform for general-purpose programming that allows users to build network applications quickly. By leveraging JavaScript on both the front-end and the back-end, development can be more consistent and be designed within the same system.
In this guide, you’ll install Node.js on a Debian 8 server. Debian 8 contains a version of Node.js in its default repositories, but this version is outdated, so you’ll explore two methods to install the latest version of Node.js on your system.

Prerequisites #

To follow this tutorial, you need:

A Debian 8 server with a non-root user with sudo privileges. You can set up a user with these privileges in our Initial Server Setup with Debian 8 guide.

How To Install Using a PPA #

The quickest and easiest way to get the most recent version of Node.js on your server is to add the PPA (personal package archive) maintained by NodeSource. This will have more up-to-date versions of Node.js than the official Debian repositories. It also lets you choose between Node.js v4.x (the older long-term support version, supported until April of 2017), v6.x (the more recent LTS version, which will be supported until April of 2018), and Node.js v7.x (the current actively developed version).
First, install the PPA in order to get access to its contents. Make sure you’re in your home directory, and use curl to retrieve the installation script for your preferred version, making sure to replace 6.x with the correct version string:

cd ~
curl -sL https://deb.nodesource.com/setup_6.x -o nodesource_setup.sh

You can inspect the contents of this script with nano (or your preferred text editor):

nano nodesource_setup.sh

And run the script under sudo:

sudo bash nodesource_setup.sh

The PPA will be added to your configuration and your local package cache will be updated automatically. After running the setup script from nodesource, you can install the Node.js package in the same way that you did above:

sudo apt-get install nodejs

The nodejs package contains the nodejs binary as well as npm, so you don’t need to install npm separately. However, in order for some npm packages to work (such as those that require compiling code from source), you will need to install the build-essential package:

sudo apt-get install build-essential

How To Install Using nvm #

An alternative to installing Node.js through apt is to use a specially designed tool called nvm, which stands for “Node.js version manager”. Using nvm, you can install multiple, self-contained versions of Node.js which will allow you to control your environment easier. It will give you on-demand access to the newest versions of Node.js, but will also allow you to target previous releases that your app may depend on.
To start off, we’ll need to get the software packages from our Debian repositories that will allow us to build source packages. The nvm command will leverage these tools to build the necessary components:

sudo apt-get update
sudo apt-get install build-essential libssl-dev

Once the prerequisite packages are installed, you can pull down the nvm installation script from the project’s GitHub page. The version number may be different, but in general, you can download it with curl:

curl -sL https://raw.githubusercontent.com/creationix/nvm/v0.32.0/install.sh -o install_nvm.sh

And inspect the installation script with nano:

nano install_nvm.sh

Run the script with bash:

bash install_nvm.sh

It will install the software into a subdirectory of your home directory at ~/.nvm. It will also add the necessary lines to your ~/.profile file to make the nvm command available.
To gain access to the nvm command and its functionality, you’ll need to log out and log back in again, or you can source the ~/.profile file so that your current session knows about the changes:

source ~/.profile

Now that you have nvm installed, you can install isolated Node.js versions.
To find out the versions of Node.js that are available for installation, you can type:

nvm ls-remote

...
         v6.8.0
         v6.8.1
         v6.9.0   (LTS: Boron)
         v6.9.1   (LTS: Boron)
         v6.9.2   (Latest LTS: Boron)
         v7.0.0
         v7.1.0
         v7.2.0

As you can see, the newest version at the time of this writing is v7.2.0, but v6.9.2 is the latest long-term support release. You can install that by typing:

nvm install 6.9.2

You’ll see the following output:

Computing checksum with sha256sum
Checksums matched!
Now using node v6.9.2 (npm v3.10.9)
Creating default alias: default -> 6.9.2 (-> v6.9.2)

Usually, nvm will switch to use the most recently installed version. You can explicitly tell nvm to use the version we just downloaded by typing:

nvm use 6.9.2

You can see the version currently being used by the shell by typing:

node -v

v6.9.2

If you have multiple Node.js versions, you can see which ones are installed by typing:

nvm ls

If you wish to make one of the versions the default, you can type:

nvm alias default 6.9.2

This version will be automatically selected when you open a new terminal session. You can also reference it by the alias like this:

nvm use default

Each version of Node.js will keep track of its own packages and has npm available to manage these.
You can have npm install packages to the Node.js project’s ./node_modules directory by using the normal format. For example, for the express module:

npm install express

If you’d like to install it globally (making it available to the other projects using the same Node.js version), you can add the -g flag:

npm install -g express

This will install the package in:

~/.nvm/node_version/lib/node_modules/package_name

Installing globally will let you run the commands from the command line, but you’ll have to link the package into your local sphere to require it from within a program:

npm link express

You can learn more about the options available to you with nvm by typing:

nvm help

Conclusion #

As you can see, there are a quite a few ways to get up and running with Node.js on your Debian 8 server. Your circumstances will dictate which of the above methods is the best idea for your circumstance. While the packaged version in Ubuntu’s repository is the easiest, the nvm method is definitely much more flexible.