Node Web Development - Second Edition: JavaScript is no longer just for browsers and this exciting introduction to Node.js will show you how to build data-intensive applications that run in real time. Benefit from an easy, step-by-step approach that really works.

Node runs on POSIX-like operating systems, the various UNIX derivatives (Solaris, and so on), or workalikes (Linux, Mac OS X, and so on), as well as on Microsoft Windows, thanks to the extensive assistance from Microsoft. Indeed, many of the Node built-in functions are direct corollaries to POSIX system calls. It can run on machines both large and small, including the tiny ARM devices such as the Raspberry Pi microscale embeddable computer for DIY software/hardware projects.

Node is now available via package management systems, limiting the need to compile and install from source.

Installing from source requires having a C compiler (such as GCC), and Python 2.7 (or later). If you plan to use encryption in your networking code you will also need the OpenSSL cryptographic library. The modern UNIX derivatives almost certainly come with these, and Node's configure script (see later when we download and configure the source) will detect their presence. If you should have to...

The preferred method for installing Node, now, is to use the versions available in package managers such as apt-get, or MacPorts. Package managers simplify your life by helping to maintain the current version of the software on your computer and ensuring to update dependent packages as necessary, all by typing a simple command such as apt-get update. Let's go over this first.

$ sudo port search nodejs
nodejs @0.10.6 (devel, net)
    Evented I/O for V8 JavaScript

nodejs-devel @0.11.2 (devel, net)
    Evented I/O for V8 JavaScript

Found 2 ports.
--
npm @1.2.21 (devel)
    node package manager
$ sudo port install nodejs npm
.. long log of downloading...

StrongLoop (http://strongloop.com) has put together a supported version of Node that is prepackaged with several useful tools. This is a Node distribution in the same sense in which Fedora or Ubuntu are Linux distributions. StrongLoop brings together several useful packages, some of which were written by StrongLoop. StrongLoop tests the packages together, and distributes installable bundles through their website.

The packages in the distribution include Express, Passport, Mongoose, Socket.IO, Engine.IO, Async, and Request. We will use all of those modules in this book.

To install, navigate to the company home page and click on the Products link. They offer downloads of precompiled packages for both RPM and Debian Linux systems, as well as Mac OS X and Windows. Simply download the appropriate bundle for your system.

For the RPM bundle, type the following:

$ sudo rpm -i bundle-file-name

For the Debian bundle, type the following:

$ sudo dpkg -i bundle...

Installing the pre-packaged Node distributions is currently the preferred installation method. However, installing Node from source is desirable in a few situations:

Now that you have the high-level view, let's get our hands dirty mucking around in some build scripts. The general process follows the usual configure, make, and make install routine that you may already have performed with other open source software packages. If not, don't worry, we'll guide you through the process.

The official installation instructions are in the Node wiki at https://github.com/joyent/node/wiki/Installation.

The developer tools (such as GCC) are an optional installation on Mac OS X. There are two ways to get those tools, both of which are free. On the OS X installation DVD is a directory labeled Optional Installs, in which there is a package installer for—among other things—the developer tools, including Xcode.

The other method is to download the latest copy of Xcode (for free) from http://developer.apple.com/xcode/.

Most other POSIX-like systems, such as Linux, include a C compiler with the base system.

$ mkdir src
$ cd src
$ wget http://nodejs.org/dist/v0.10.7/node-v0.10.7.tar.gz
$ tar xvfz node-v0.10.7.tar.gz
$ cd node-v0.10.7

Now that you've installed Node, we want to do two things; verify that the installation was successful, and familiarize you with the command-line tools.

$ node –-help
Usage: node [options] [ -e script | script.js ] [arguments]
       node debug script.js [arguments]

Options:
  -v, --version        print node's version
  -e, --eval script    evaluate script
  -p, --print          print result of --eval
  -i, --interactive    always...

Node by itself is a pretty basic system, being a JavaScript interpreter with a few interesting asynchronous I/O libraries. One of the things which makes Node interesting is the rapidly growing ecosystem of third party modules for Node. At the center of that ecosystem is npm. The modules can be downloaded at source and assembled manually for use with Node programs. The npm command gives us a simpler way; npm is the de-facto standard package manager for Node and it greatly simplifies downloading and using these modules. We will talk about npm at length in the next chapter.

The sharp-eyed will have noticed that npm is already installed via all the installation methods already discussed. In the past, npm was installed separately, but today it is bundled with Node.

Now that we have npm installed, let's take it for a quick spin. Hexy is a utility program for printing hex dumps of files. It serves our purpose right now in giving us something to quickly install and try...

Earlier we started a Node server from the command line. While this is useful for testing and development, it's not useful for deploying an application in any normal sense. There are normal practices for starting server processes, which differ for each operating system. Implementing a Node server means starting it similarly to the other background processes (sshd, Apache, MySQL, and so on) using, for example, start/stop scripts.

The Node project does not include start/stop scripts for any operating system. It can be argued that it would be out of place for Node to include such scripts. Instead, Node server applications should include such scripts. The traditional way is that the init daemon manages background processes using scripts in the /etc/init.d directory. On Fedora and Red Hat, that's still the process, but other operating systems use other daemon managers such as Upstart or launchd.

Writing these start/stop scripts is only a part of what's required...

We learned a lot in this chapter, about installing Node, using its command-line tools, and how to run a Node server. We also breezed past a lot of details that will be covered later in the book, so be patient.

Specifically, we covered:

Now that we've seen how to set up the basic system, we're ready to start working on implementing applications with Node. First we must learn the basic building block of Node applications, modules, which is the topic of the next chapter.