The quickest, and easiest, way to install Nginx is to simply use your OS-provided version. Most of the time, these are kept fairly updated; however, for some Linux distributions focusing on stability, you may only have older versions of Nginx available. Sometimes, your Linux distribution may provide multiple versions of Nginx with different compile flags.

In general, before embarking on a more complex journey, we should check if we can use the easy solution. For a Debian-based operating system, we first find the Nginx compiles available then get the info for the one we want:

apt-cache search nginx
apt-cache show PACKAGE_NAME
apt-get install PACKAGE_NAME

For Red Hat Linux-based operating systems, we need to enable the EPEL repo first and then do the same:

yum install epel-release
yum search nginx
yum info PACKAGE_NAME
yum install PACKAGE_NAME

If the version provided is current enough, then you're ready to configure Nginx in the next chapter.

If the version provided by your distribution is too old, then Nginx provides packages for RHEL/CentOS distributions as well as Debian/Ubuntu distributions.

To set up a yum repository for RHEL/CentOS, create a file named /etc/yum.repos.d/nginx.repo with the following contents:

[nginx]
name=nginx repo
baseurl=http://nginx.org/packages/OS/OSRELEASE/$basearch/
gpgcheck=0
enabled=1

Replace OS with rhel or centos, depending on the distribution used, and OSRELEASE with 6 or 7, for versions 6.x or 7.x, respectively. Afterwards, Nginx can now be installed with yum:

yum install nginx

For Debian-based distributions, we need to first use their signing key to authenticate the package signatures. Download the following file first from http://nginx.org/keys/nginx_signing.key.

Then run the following command:

sudo apt-key add nginx_signing.key

With the key added, we can now add the Nginx repository to our sources.list found in /etc/apt/sources.list. For Debian, we add the following lines:

deb http://nginx.org/packages/debian/ codename nginx
deb-src http://nginx.org/packages/debian/ codename nginx

Where codename is either jessie or stretch depending on your version of Debian. For Ubuntu, we use the following dependencies:

deb http://nginx.org/packages/ubuntu/ codename nginx
deb-src http://nginx.org/packages/ubuntu/ codename nginx

Where codename is one of trusty, xenial, or zesty depending on your version of Ubuntu. Finally, we can install Nginx with the apt-get command option:

apt-get update
apt-get install nginx

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.

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.

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

[alex@example.com ~]$ 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:

[root@example.com ~]# yum groupinstall "Development Tools"  

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

[root@example.com ~]# 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 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:

[root@example.com ~]# yum install pcre pcre-devel

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

[root@example.com ~]# yum install pcre*

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

[root@example.com ~]# 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:

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:

[root@example.com ~]# yum install zlib zlib-devel

Using apt-get, execute the following command:

[root@example.com ~]# apt-get install zlib1g zlib1g-dev

These packages install quickly and have no known dependency issues.

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:

[root@example.com ~]# yum install openssl openssl-devel

Using apt-get, execute the following command:

[root@example.com ~]# apt-get install openssl libssl-dev

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