Configure options

There are usually three steps when building an application from source—configuration, compilation, and 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 files being located in a random folder.

The process consists of appending certain switches to the configure script that comes with the source code. We will discover the three types of switches that you can activate; but let us first study the easiest way to proceed.

The easy way

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:

[alex@example.com nginx-1.13.8]# ./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, please make sure you 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:

[alex@example.com nginx-1.13.8]# make

The make command will compile the application. This step should not cause any errors as long as the configuration went fine:

[root@example.com nginx-1.13.8]# 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.

Path options

When running the configure command, you are offered the chance to enable some switches that let you specify the directory or file paths for a variety of elements. Please note that the options offered by the configuration switches may change according to the version you downloaded. The following options listed are valid with the stable version, as of release 1.13.8. 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:

[alex@example.com nginx-1.13.8]# ./configure --conf-path=/etc/nginx/nginx.conf

Here is an exhaustive list of the configuration switches for configuring paths:

Switch	Usage	Default value
`--prefix=...`	The base folder in which Nginx will be installed.	`/usr/local/nginx` If you configure other switches using relative paths, they will connect to the base folder. For example; specifying `--conf-path=conf/nginx.conf` will result in your configuration file being found at `/usr/local/nginx/conf/nginx.conf`.
`--sbin-path=...`	The path where the Nginx binary file should be installed.	`<prefix>/sbin/nginx`.
`--conf-path=...`	The path of the main configuration file.	`<prefix>/conf/nginx.conf`.
`--error-log-path=...`	The location of your error log. Error logs can be configured very accurately in the configuration files. This path only applies in case you do not specify any error logging directive in your configuration.	`<prefix>/logs/error.log`.
`--pid-path=...`	The path of the Nginx PID file. You can specify the PID file path in the configuration file. If that's not the case, the value you specify for this switch will be used.	`<prefix>/logs/nginx.pid`. The PID file is a simple text file containing the process identifier. It is placed in a well-defined location so that other applications can easily find the PID of a running program.
`--lock-path=...`	The location of the lock file. Again, it can be specified in the configuration file, but if it isn't, this value will be used.	`<prefix>/logs/nginx.lock`. The lock file allows other applications to determine whether or not the program is running. In the case of Nginx, it is used to make sure that the process is not started twice.
`--with-perl_modules_path=...`	Defines the path to the Perl modules. This switch must be defined if you want to include additional Perl modules.	NA
`--with-perl=...`	Path to the Perl binary file; used for executing Perl scripts. This path must be set if you want to allow execution of Perl scripts.	NA
`--http-log-path=...`	Defines the location of access logs. This path is used only if the access log directive is unspecified in the configuration files.	`<prefix>/logs/access.log`.
`--http-client-body-temp-path=...`	Directory used for storing temporary files generated by client requests.	`<prefix>/client_body_temp`.
`--http-proxy-temp-path=...`	Location of the temporary files used by the proxy.	`<prefix>/proxy_temp`.
`--http-fastcgi-temp-path=...` `--http-uwsgi-temp-path=...` `--http-scgi-temp-path=...`	Location of the temporary files used by the HTTP FastCGI, uWSGI, and SCGI modules.	Respectively `<prefix>/fastcgi_temp`,`<prefix>/uwsgi_temp`, and `<prefix>/scgi_temp`.
`--builddir=...`	Location of the application build.	NA

Prerequisite options

Prerequisites come in the form of libraries and binaries. You should by now have them all installed on your system. Yet, even though they are present on your system, there may be occasions where the configuration script cannot 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 for prerequisites using the following switches. Miscellaneous prerequisite-related options are grouped together.

Compiler options	Usage
`--with-cc=...`	Specifies an alternate location for the C compiler.
`--with-cpp=...`	Specifies an alternate location for the C preprocessor.
`--with-cc-opt=...`	Defines additional options to be passed to the C compiler command line.
`--with-ld-opt=...`	Defines additional options to be passed to the C linker command line.
`--with-cpu-opt=...`	Specifies a different target processor architecture, from these values: `pentium`, `pentiumpro`, `pentium3`, `pentium4`, `athlon`, `opteron`, `sparc32`, `sparc64`, and `ppc64`.
`--with-compat`	Enables dynamic module compatibility. Should be enabled if planning to use dynamic modules.

PCRE options	Usage
`--without-pcre`	PCRE option disables usage of the PCRE library. This setting is not recommended, as it will remove support for regular expressions, consequently disabling the rewrite module.
`--with-pcre`	Forces usage of the PCRE library.
`--with-pcre=...`	Allows you to specify the path of the PCRE library source code.
`--with-pcre-opt=...`	Additional options for building the PCRE library.
`--with-pcre-jit=...`	Build PCRE with JIT compilation support.

zlib options	Usage
`--with-zlib=...`	Specifies the path to the zlib library sources.
`--with-zlib-opt=...`	Additional options for building the zlib library.
`--with-zlib-asm=...`	Uses assembler optimizations for these target architectures, `pentium`, `pentiumpro`.

OpenSSL options	Usage
`--with-openssl=...`	Specifies the path of OpenSSL library sources.
`--with-openssl-opt=...`	Additional options for building the OpenSSL library.

Libatomic	Usage
`--with-libatomic=...`	Forces usage of the `libatomic_ops` library on systems other than x86, amd64, and sparc. This library allows Nginx to perform atomic operations directly instead of resorting to lock files. Depending on your system, it may result in a decrease in `SEGFAULT` errors and possibly a higher request serving rate.
`--with-libatomic=...`	Specifies the path of the Libatomic library sources.

Module options

Modules, which will be detailed in Chapter 3, HTTP Configuration, and further, 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.

Modules enabled by default

The following switches allow you to disable modules that are enabled by default:

Modules enabled by default	Description
`--without-http_charset_module`	Disables the charset module for re-encoding web pages.
`--without-http_gzip_module`	Disables the gzip compression module.
`--without-http_ssi_module`	Disables the server-side include module.
`--without-http_userid_module`	Disables the user ID module providing user identification via cookies.
`--without-http_access_module`	Disables the access module allowing access configuration for IP address ranges.
`--without-http_auth_basic_module`	Disables the basic authentication module.
`--without-mirror`	Disables the mirror module, used for creating mirror requests to alternative backends.
`--without-http_autoindex_module`	Disables the automatic index module.
`--without-http_geo_module`	Disables the geo module allowing you to define variables depending on IP address ranges.
`--without-http_map_module`	Disables the map module that allows you to declare map blocks.
`--without-http_split_clients_module`	Disables the split clients module, which can be used for A/B testing.
`--without-http_referer_module`	Disables the referer control module.
`--without-http_rewrite_module`	Disables the rewrite module.
`--without-http_proxy_module`	Disables the proxy module for transferring requests to other servers.
`--without-http_fastcgi_module` `--without-http_uwsgi_module` `--without-http_scgi_module`	Disables the FastCGI, uWSGI, or SCGI modules for interacting with respectively FastCGI, uWSGI, or SCGI processes.
`--without-http_memcached_module`	Disables the memcached module for interacting with the memcache daemon.
`--without-http_limit_conn_module`	Disables the limit connections module for restricting resource usage according to defined zones.
`--without-http_limit_req_module`	Disables the limit requests module allowing you to limit the amount of requests per user.
`--without-http_empty_gif_module`	Disables the empty gif module that serves a blank GIF image from memory.
`--without-http_browser_module`	Disables the browser module that interprets the user agent string.
`--without-http_upstream_hash_module`	Disables the upstream hash module providing the hash directive in upstream blocks.
`--without-http_upstream_ip_hash_module`	Disables the upstream IP hash module providing the `ip_hash` directive in upstream blocks.
`--without-http_upstream_least_conn_module`	Disables the upstream least—conn module providing the `least_conn` directive in upstream blocks.
`--without-http_upstream_keepalive_module`	Disables the upstream keepalive module.
`--without-http_upstream_zone_module`	Disables the upstream shared memory zone module.

Modules disabled by default

The following switches allow you to enable modules that are disabled by default:

Modules disabled by default	Description
`--with-http_ssl_module`	Enables the SSL module for serving pages using HTTPS.
`--with-http_v2`	Enables support for HTTP/2.
`--with-http_realip_module`	Enables the realip module, for reading the real IP address from the request header data.
`--with-http_addition_module`	Enables the addition module which lets you append or prepend data to the response body.
`--with-http_xslt_module`	Enables the xslt module for applying XSL transformations to XML documents. You will need to install the `libxml2` and `libxslt` libraries on your system if you wish to compile these modules. You can pass this setting to the dynamic flag to compile as a dynamic module.
`--with-http_image_filter_module`	Enables the image_filter module, which lets you apply modifications to images. You will need to install the `libgd` library on your system if you wish to compile this module. You can pass it the dynamic flag to compile as the dynamic module.
`--with-http_geoip_module`	Enables the geoip module for achieving geographic localization using MaxMind's GeoIP binary database. You will need to install the `libgeoip` library on your system if you wish to compile this module. You can pass it the dynamic flag to compile as dynamic module.
`--with-http_sub_module`	Enables the substitution (sub) module for replacing text in web pages.
`--with-http_dav_module`	Enables the WebDAV module (distributed authoring and versioning via the web).
`--with-http_flv_module`	Enables the FLV module for special handling of `.flv` (flash video) files.
`--with-http_mp4_module`	Enables the MP4 module for special handling of `.mp4` video files.
`--with-http_gzip_static_module`	Enables the gzip static module for sending pre-compressed files.
`--with-http_auth_request_module`	Enables the auth_request module. This module allows you to delegate the HTTP authentication mechanism to a back-end server via a subrequest. The status code of the response can be stored in a variable.
`--with-http_random_index_module`	Enables the random_index module for picking a random file as the directory index.
`--with-http_secure_link_module`	Enables the secure_link module to check the presence of a keyword in the URL.
`--with-http_stub_status_module`	Enables the stub status module, which generates a server statistics and information page.
`--with-google_perftools_module`	Enables the Google performance tools module.
`--with-http_degradation_module`	Enables the degradation module, which controls the behavior of your server depending on current resource usage.
`--with-http_perl_module`	Enables the perl module allowing you to insert Perl code directly into your Nginx configuration files, and to make Perl calls from SSI.
`--with-http_gunzip_module`	Enables the gunzip module, which offers to decompress a gzip-encoded response from a back-end server before forwarding it to the client.

Miscellaneous options

Other options are available in the configuration script, for example, regarding the streaming modules, the mail server proxy feature, or event management.

Streaming server options	Usage
`--with-stream`	Enables the stream module for proxying data streams over TCP/UDP.
`--with-mail_ssl_module`	Enables SSL support for the mail server proxy. It is disabled by default.
`--without-mail_pop3_module`	Disables the POP3 module for the mail server proxy. It is enabled by default when the mail server proxy module is enabled.
`--without-mail_imap_module`	Disables the IMAP4 module for the mail server proxy. It is enabled by default when the mail server proxy module is enabled.
`--without-mail_smtp_module`	Disables the SMTP module for the mail server proxy. It is enabled by default when the mail server proxy module is enabled.

Mail server options	Usage
`--with-mail`	Mail server proxy option enables mail the server proxy module. Supports POP3, IMAP4, SMTP. It is disabled by default.
`--with-mail_ssl_module`	Enables SSL support for the mail server proxy. It is disabled by default.
`--without-mail_pop3_module`	Disables the POP3 module for the mail server proxy. It is enabled by default when the mail server proxy module is enabled.
`--without-mail_imap_module`	Disables the IMAP4 module for the mail server proxy. It is enabled by default when the mail server proxy module is enabled.
`--without-mail_smtp_module`	Disables the SMTP module for the mail server proxy. It is enabled by default when the mail server proxy module is enabled.

Event management (allows you to select an event notification system for the Nginx sequencer. For advanced users only)	Usage
`--with-rtsig_module`	Enables the rtsig module to use `rtsig` as the event notification mechanism.
`--with-select_module`	Enables the select module to use select as the event notification mechanism. By default, this module is enabled unless a better method is found on the system:`kqueue`, `epoll`, `rtsig`, or `poll`.
`--without-select_module`	Disables the select module.
`--with-poll_module`	Enables the poll module to use poll as the event notification mechanism. By default, this module is enabled if available, unless a better method is found on the `system-kqueue`, `epoll`, or `rtsig`.
`--without-poll_module`	Disables the poll module.

User and group options	Usage
`--user=...`	Default user account for starting the Nginx worker processes. This setting is used only if you omit to specify the user directive in the configuration file.
`--group=...`	Default user group for starting the Nginx worker processes. This setting is used only if you omit to specify the group directive in the configuration file.

`--without-http`	Disables the HTTP server.
`--without-http-cache`	Disables HTTP caching features.
`--add-module=PATH`	Adds a third-party module to the compile process by specifying its path. This switch can be repeated indefinitely if you wish to compile multiple modules.
`--with-debug`	Enables additional debugging information to be logged.
`--with-file-aio`	Enables support for Asynchronous IO Disk Operations or AIOs.
`--build=name`	Optionally set a name for this compile of Nginx. Can be used for internal identification.

Configuration examples

Here are a few examples of configuration commands that may be used for various cases. In these examples, the path switches were omitted as they are specific to each system and leaving the default values may simply function correctly.

Be aware that these configurations do not include additional third-party modules. Please refer to Chapter 5, PHP and Python with Nginx, for more information about installing add-ons.

About the prefix switch

During the configuration, you should take particular care over the --prefix switch. Many of the future configuration directives (which we will cover in further chapters) will be based on the path you select at this point. While it is not a an insoluble 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 path 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 you use a different prefix for each version you will be using:

./configure --prefix=/usr/local/nginx-1.13.8

Additionally, to make future changes simpler, you may create a symbolic link /usr/local/nginx pointing to /usr/local/nginx-1.13.8. 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.

Regular HTTP and HTTPS servers

The first example describes a situation where the most important features and modules for serving HTTP and HTTPS content are enabled, and 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 were left out. The reason 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 for serving HTTPS content and optionally, the realip module for retrieving your visitors' IP addresses in case you are running Nginx as a backend server.

All modules enabled

The next situation: the entire package. All modules are enabled 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_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 GeoIP 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 instance by running yum install libxml2 or apt-get install libxml2.

Mail server proxy

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. The related features and modules are all enabled:

./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 the previously listed commands, the user and group used for running the Nginx worker processes will be www-data, which implies that this user and group must exist on your system.

Build configuration issues

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.

Make sure you installed the prerequisites

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. Please refer to the prerequisites section at the beginning of this chapter. Note that other prerequisites, such as LibXML2 or LibXSLT, might be required for enabling 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.

Directories exist and are writable

Always remember to check the obvious; everyone makes even the simplest of mistakes sooner or later. Make sure 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.

Compiling and installing

The configuration process is of the 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:

[alex@example.com nginx-1.13.8]$ make

A successful build should result in a final message appearing: make[1]: leaving directory followed by the project source path.

Again, problems might occur at compile time. Most of these problems can originate in missing prerequisites or invalid paths specified. If this occurs, run the configure command again and triple-check the switches and all of the prerequisite options. It may also occur that you downloaded a too recent version of the prerequisites that might 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:

[root@example.com nginx-1.13.8]# make install

The make install command executes the install section of the makefile. 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 for storing 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.

You might require root privileges for installing the application in the /usr/local/ folder, depending on the folder permissions.