There are usually three steps when building an application from source: the configuration, the compilation, and the installation. The configuration step allows you to select a number of options that will not be editable after the program is built, as it has a direct impact on the project binaries. Consequently, it is a very important stage that you need to follow carefully if you want to avoid surprises later, such as the lack of a specific module or having configuration files located in a random folder.
The process consists of appending certain switches to the configure command that comes with the source code. The three types of switches that you can activate will be covered later, but let's first study the easiest way to proceed.
If, for some reason, you do not want to bother with the configuration step, such as for testing purposes or simply because you will be recompiling the application in the future, you may simply use the configure command with no switches. Execute the following three commands to build and install a working version of Nginx, starting with the configure command:
[[email protected] nginx-1.8.0]# ./configure
Running this command should initiate a long procedure of verifications to ensure that your system contains all of the necessary components. If the configuration process fails, check the prerequisites section again, as it is the most common cause of errors. For information about why the command failed, you may also refer to the objs/autoconf.err file, which provides a more detailed report. The make command will compile the application. This step should not cause any errors as long as the configuration went fine.
[[email protected] nginx-1.8.0]# make [[email protected] nginx-1.8.0]# make install
This last step will copy the compiled files as well as other resources to the installation directory, by default, /usr/local/nginx. You may need to be logged in as root to perform this operation, depending on permissions granted to the /usr/local directory.
Again, if you build the application without configuring it, you take the risk of missing out on a lot of features, such as the optional modules and others that we are about to discover.
When running the configure command, you are offered the possibility to enable some switches that let you specify the directory or file paths for a variety of elements. Note that the options offered by the configuration switches may change according to the version you downloaded. The options listed below are valid with the stable version, as of release 1.8.0. If you use another version, run the ./configure --help command to list the available switches for your setup.
Using a switch typically consists of appending some text to the command line, for instance, using the --conf-path switch:
[[email protected] nginx-1.8.0]# ./configure --conf-path=/etc/nginx/nginx.conf
Here is an exhaustive list of the configuration switches for configuring paths:
Prerequisites come in the form of libraries and binaries. You should, by now, have them all installed on your system. However, even though they are present on your system, there may be occasions where the configuration script is unable to locate them. The reasons might be diverse, for example, if they were installed in non-standard directories.
In order to solve such problems, you are given the option to specify the path of prerequisites using the following switches (miscellaneous prerequisite-related options have been grouped together):
Modules, which will be detailed in Chapter 4, Module Configuration, need to be selected before compiling the application. Some are enabled by default and some need to be enabled manually, as you will see in the following table.
The following switches allow you to disable modules that are enabled by default:
The following switches allow you to enable modules that are disabled by default:
Other options are available in the configuration script, for example, regarding the mail server proxy feature or event management. These have been enlisted as follows:
Here are a few examples of configuration commands that may be used for various cases. In these examples, the path switches have been omitted, as they are specific to each system and leaving the default values may simply function correctly.
Note
Be aware that these configurations do not include additional third-party modules. Please refer to Chapter 4, Module Configuration, for more information about installing add-ons.
During the configuration, you should take particular care of the --prefix switch. Many of the future configuration directives (that will be approached in further chapters) will be based on the path you select at this point. While it is not a definitive problem since absolute paths can still be employed, you should know that the prefix cannot be changed once the binaries have been compiled.
There is also another issue that you may run into if you plan to keep up with the times and update Nginx as new versions are released. The default prefix (if you do not override the setting by using the --prefix switch) is /usr/local/nginx. This is a path that does not include the version number. Consequently, when you upgrade Nginx, if you do not specify a different prefix, the new install files will override the previous ones, which among other problems, could potentially erase your currently running binaries.
It is thus recommended to use a different prefix for each version you will be using. Use the following command to specify a prefix that is specific to version 1.8.0:
./configure --prefix=/usr/local/nginx-1.8.0
Additionally, to make future changes simpler, you may create a symbolic link /usr/local/nginx pointing to /usr/local/nginx-1.8.0. Once you upgrade, you can update the link to make it point to /usr/local/nginx-newer.version. This will allow the init script to always make use of the latest installed version of Nginx.
The first example describes a situation where the most important features and modules to serve HTTP and HTTPS content are enabled, and the mail-related options are disabled:
./configure --user=www-data --group=www-data --with-http_ssl_module --with-http_realip_module
As you can see, the command is rather simple and most switches have been left out. The reason for this is that the default configuration is rather efficient, and most of the important modules are enabled. You will only need to include the http_ssl module to serve HTTPS content, and optionally, the real IP module to retrieve your visitors' IP addresses in case you are running Nginx as backend server.
The next situation includes all available modules, and it is up to you whether you want to use them or not at runtime:
./configure --user=www-data --group=www-data --with-http_ssl_module --with-http_realip_module --with-http_addition_module --with-http_xslt_module --with-http_image_filter_module --with-http_geoip_module --with-http_sub_module --with-http_dav_module --with-http_flv_module --with-http_mp4_module --with-http_gzip_static_module --with-http_random_index_module --with-http_secure_link_module --with-http_stub_status_module --with-http_perl_module --with-http_degradation_module --with-http_spdy_module --with-http_gunzip_module --with-http_auth_request_module
This configuration opens up a wide range of possible configuration options. Chapter 3, HTTP Configuration, to Chapter 6, Apache and Nginx Together, provide more detailed information on module configuration.
With this setup, all optional modules are enabled, thus requiring additional libraries to be installed—libgeoip for the Geo IP module, libgd for the Image Filter module, libxml2, and libxslt for the XSLT module. You may install those prerequisites using your system package manager, for example, by running yum install libxml2 or apt-get install libxml2.
This last build configuration is somewhat special, as it is dedicated to enabling mail server proxy features—a darker and less documented side of Nginx. You can enable all mail related features through the following command:
./configure --user=www-data --group=www-data --with-mail --with-mail_ssl_module
If you wish to completely disable the HTTP serving features and only dedicate Nginx to mail proxying, you may add the --without-http switch.
In some cases, the configure command may fail—after a long list of checks, you may receive a few error messages on your terminal. In most (if not all) cases, these errors are related to missing prerequisites or unspecified paths.
In such cases, proceed with the following verifications carefully to make sure you have all it takes to compile the application, and optionally, consult the objs/autoconf.err file for more details about the compilation problem. This file is generated during the configure process and will tell you exactly which part of the process failed.
There are basically four main prerequisites: GCC, PCRE, zlib, and OpenSSL. The last three are libraries that must be installed in two packages: the library itself and its development sources. Make sure you have installed both for each of them. Refer to the prerequisites section at the beginning of this chapter for additional information. Note that other prerequisites such as LibXML2 or LibXSLT may be required to enable extra modules (for example, in the case of the HTTP XSLT module).
If you are positive that all of the prerequisites were installed correctly, perhaps the issue comes from the fact that the configure script is unable to locate the prerequisite files. In that case, make sure that you include the configuration switches related to file paths, as described earlier.
For example, the following switch allows you to specify the location of the OpenSSL library files:
./configure [...] --with-openssl=/usr/lib64
The OpenSSL library file will be looked for in the specified folder.
Always remember to check the obvious; everyone makes even the simplest of mistakes sooner or later. Make sure that the directory you placed the Nginx files in has read and write permissions for the user running the configuration and compilation scripts. Also ensure that all paths specified in the configure script switches are existing, valid paths.
The configuration process is of utmost importance—it generates a makefile for the application depending on the selected switches and performs a long list of requirement checks on your system. Once the configure script is successfully executed, you can proceed with compiling Nginx.
Compiling the project equates to executing the make command in the project source directory:
[[email protected] nginx-1.8.0]$ make
A successful build should result in the appearance of a final message: make[1]: leaving directory. This should be followed by the project source path.
Again, problems might occur at compile time. Most of these problems can originate in missing prerequisites or the specification of invalid paths. If this occurs, run the configure command again and triple-check the switches and all of the prerequisite options. It may also so happen that you downloaded an overly recent version of the prerequisites, which may not be backwards compatible. In such cases, the best option is to visit the official website of the missing component and download an older version.
If the compilation process was successful, you are ready for the next step: installing the application. The following command must be executed with root privileges:
[[email protected] nginx-1.8.0]# make install
The make install command executes the install section of the make file. In other words, it performs a few simple operations, such as copying binaries and configuration files to the specified install folder. It also creates directories to store log and HTML files if these do not already exist. The make install step is not generally a source of problems, unless your system encounters an exceptional error, such as a lack of storage space or memory.