Thursday, June 18, 2015

Install Node.js on an Ubuntu 14.04 Physical server

Introduction

Node.js is a Javascript platform for server-side 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, we'll show you how to get started with Node.js on an Ubuntu 14.04 LTS Physical server.

How To Install the Distro-Stable Version

Ubuntu 14.04 contains a version of Node.js in its default repositories that can be used to easily provide a consistent experience across multiple servers. The version in the repositories is 0.10.25. This will not be the latest version, but it should be quite stable.
In order to get this version, we just have to use the apt package manager. We should refresh our local package index prior and then install from the repositories:

sudo apt-get update
sudo apt-get install nodejs
 
If the package in the repositories suits your needs, this is all that you need to do to get set up with Node.js. In most cases, you'll also want to also install npm, which is the Node.js package manager. You can do this by typing:

sudo apt-get install npm
 
This will allow you to easily install modules and packages to use with Node.js.
Because of a conflict with another package, the executable from the Ubuntu repositories is called nodejs instead of node. Keep this in mind as you are running software.
Below, we'll discuss some more flexible methods of installation.

How To Install Using a PPA

An alternative that can get you a more recent version of Node.js is to add a PPA (personal package archive) maintained by NodeSource. This will probably have more up-to-date versions of Node.js than the official Ubuntu repositories.
First, you need to install the PPA in order to get access to its contents:

curl -sL https://deb.nodesource.com/setup | sudo bash -
 
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 building from source), you will need to install the build-essentials 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 Ubuntu repositories that will allow us to build source packages. The nvm script 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 and install it with the following syntax:

curl https://raw.githubusercontent.com/creationix/nvm/v0.16.1/install.sh | sh
 
This will download the script and run it. 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 use the file.
To gain access to the nvm 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
. . .
 v0.11.6
 v0.11.7
 v0.11.8
 v0.11.9
v0.11.10
v0.11.11
v0.11.12
v0.11.13
As you can see, the newest version at the time of this writing is v0.11.13. You can install that by typing:

nvm install 0.11.13
 
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 0.11.13
 
When you install Node.js using nvm, the executable is called node. You can see the version currently being used by the shell by typing:

node -v
v.0.11.13
 
If you have multiple Node.js versions, you can see what is installed by typing:

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

nvm alias default 0.11.13
 
This version will be automatically selected when a new session spawns. 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:

npm install express 
 
If you'd like to install it globally (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 use 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