Compiling from source

There are situations where compiling Nginx from source is preferable. It gives us the most flexibility regarding modules, so we can customize better for our intended usage. For example, we could compile a very lean version for embedded hardware.

Additionally, we can make sure we use the latest version of Nginx and have all new features available to us. Keep in mind, though, that when installing software from source you are responsible for keeping it updated. Nginx, just like every other piece of software, sometimes finds security issues that it needs to address. An OS package is much easier to update than a source install, but so long as you're aware of the need to maintain it yourself, there is absolutely no problem.

Depending on the optional modules that you select at compile time, you will perhaps need different prerequisites. We will guide you through the process of installing the most common ones, such as GCC, PCRE, zlib, and OpenSSL.

GNU Compiler Collection

Nginx is a program written in C, so you will first need to install a compiler tool such as the GNU Compiler Collection (GCC) on your system. GCC may already be present on your system, but if that is not the case you will have to install it before going any further.

GCC is a collection of free open source compilers for various languages – C, C++, Java, Ada, FORTRAN, and so on. It is the most commonly used compiler suite in the Linux world, and Windows versions are also available. A vast number of processors are supported, such as x86, AMD64, PowerPC, ARM, MIPS, and more.

First, make sure it isn't already installed on your system:

[[email protected] ~]$ gcc

If you get the following output, it means that GCC is correctly installed on your system and you can skip to the next section:

gcc: no input files

If you receive the following message, you will have to proceed with the installation of the compiler:

~bash: gcc: command not found  

GCC can be installed using the default repositories of your package manager. Depending on your distribution, the package manager will be vary-yum for a Red Hat Linux-based distribution, apt for Debian and Ubuntu, yast for SuSE Linux, and so on. Here is the typical way to proceed with the download and installation of the GCC package:

[[email protected] ~]# yum groupinstall "Development Tools"  

If you use apt-get, execute the following command:

[[email protected] ~]# apt-get install build-essentials

If you use another package manager with a different syntax, you will probably find the documentation with the man utility. Either way, your package manager should be able to download and install GCC correctly, after having resolved dependencies automatically. Note that this command will not only install GCC, it also proceeds with downloading and installing all common requirements for building applications from source, such as code headers and other compilation tools.

The PCRE library

The Perl Compatible Regular Expression (PCRE) library is required for compiling Nginx. The rewrite and HTTP core modules of Nginx use PCRE for the syntax of their regular expressions, as we will discover in later chapters. You will need to install two packages—pcre and pcre-devel. The first one provides the compiled version of the library, whereas the second one provides development headers and sources for compiling projects, which are required in our case.

Here are some example commands that you can run in order to install both the packages.

Using yum, execute the following command:

[[email protected] ~]# yum install pcre pcre-devel

Or you can install all PCRE-related packages using the following command:

[[email protected] ~]# yum install pcre*

If you use apt-get, use the following command:

[[email protected] ~]# apt-get install libpcre3 libpcre3-dev

If these packages are already installed on your system, you will receive a message saying something like nothing to do; in other words, the package manager did not install or update any component:

Both components are already present on the system.

The zlib library

The zlib library provides developers with compression algorithms. It is required for the use of .gzip compression in various modules of Nginx. Again, you can use your package manager to install this component as it is part of the default repositories. Similar to PCRE, you will need both the library and its source-zlib and zlib-devel.

Using yum, execute the following command:

[[email protected] ~]# yum install zlib zlib-devel

Using apt-get, execute the following command:

[[email protected] ~]# apt-get install zlib1g zlib1g-dev

These packages install quickly and have no known dependency issues.

OpenSSL

The OpenSSL project is a collaborative effort to develop a robust, commercial-grade, full-featured, and open source toolkit implementing the Secure Sockets Layer (SSL v2/v3) and Transport Layer Security (TLS v1) protocols as well as a full-strength general purpose cryptography library. The project is managed by a worldwide community of volunteers that use the internet to communicate, plan, and develop the OpenSSL toolkit and its related documentation. For more information, visit http://www.openssl.org.

The OpenSSL library will be used by Nginx to serve secure web pages. We thus need to install the library and its development package. The process remains the same here – you install openssl and openssl-devel:

[[email protected] ~]# yum install openssl openssl-devel

Using apt-get, execute the following command:

[[email protected] ~]# apt-get install openssl libssl-dev

Please be aware of the laws and regulations in your own country. Some countries do not allow the use of strong cryptography. The author, publisher, and the developers of the OpenSSL and Nginx projects will not be held liable for any violations or law infringements on your part.

Now that you have installed all of the prerequisites, you are ready to download and compile the Nginx source code.