Compiling and Installing

Overview for the impatient ¶

$ tar xzf httpd-NN.tar.gz
$ cd httpd-NN

NN must be replaced with the current version number, and PREFIX must be replaced with the filesystem path under which the server should be installed. If PREFIX is not specified, it defaults to /usr/local/apache2.

Each section of the compilation and installation process is described in more detail below, beginning with the requirements for compiling and installing Apache httpd.

Requirements ¶

The following requirements exist for building and running Apache httpd:

APR and APR-Util

Make sure you have APR and APR-Util already installed on your system. If you don't, or prefer to not use the system-provided versions, download the latest versions of both APR and APR-Util from Apache APR, unpack them into /httpd_source_tree_root/srclib/apr and /httpd_source_tree_root/srclib/apr-util (be sure the directory names do not have version numbers; for example, the APR distribution must be under /httpd_source_tree_root/srclib/apr/) and use ./configure's --with-included-apr option. On some platforms, you may have to install the corresponding -dev packages to allow httpd to build against your installed copy of APR and APR-Util.

Perl-Compatible Regular Expressions Library (PCRE2)

This library is required but not bundled with httpd. Download the source code from https://github.com/PCRE2Project/pcre2 or install it from your system's package manager. If your build system can't find the pcre2-config script installed by the PCRE2 build, point to it using the --with-pcre parameter. On some platforms, you may have to install the corresponding -dev package (e.g. libpcre2-dev or pcre2-devel) to allow httpd to build against your installed copy of PCRE2.

Disk Space

Make sure you have at least 200 MB of temporary free disk space available. After installation the server occupies approximately 50 MB of disk space. The actual disk space requirements will vary considerably based on your chosen configuration options, any third-party modules, and, of course, the size of the web site or sites that you have on the server.

ANSI-C Compiler and Build System

Make sure you have an ANSI-C compiler installed. The GNU C compiler (GCC) from the Free Software Foundation (FSF) is recommended. If you don't have GCC then at least make sure your vendor's compiler is ANSI compliant. In addition, your PATH must contain basic build tools such as make.

Accurate time keeping

HTTP protocol headers use timestamps, so your system clock must be accurate. Most Linux distributions enable systemd-timesyncd or chrony by default. Verify that time synchronization is active on your system before running a production server.

Perl 5 [OPTIONAL]

For some of the support scripts like apxs or dbmmanage (which are written in Perl) the Perl 5 interpreter is required. If no Perl 5 interpreter is found by the configure script, you will not be able to use the affected support scripts. Of course, you will still be able to build and use Apache httpd.

Download ¶

Download the source tarball from the Apache HTTP Server download site.

After downloading, it is important to verify that you have a complete and unmodified version of the Apache HTTP Server. This can be accomplished by testing the downloaded tarball against the PGP signature. Details on how to do this are available on the verification page.

Extract ¶

Extract the source from the Apache HTTP Server tarball:

$ tar xzf httpd-NN.tar.gz

This will create a new directory under the current directory containing the source code for the distribution. You should cd into that directory before proceeding with compiling the server.

Configuring the source tree ¶

The next step is to configure the httpd source tree for your particular platform and personal requirements. This is done using the script configure included in the root directory of the distribution. (Developers downloading an unreleased version of the httpd source tree will need to have autoconf and libtool installed and will need to run buildconf before proceeding with the next steps. This is not necessary for official releases.)

To configure the source tree using all the default options, type ./configure. To change the default options, configure accepts a variety of variables and command line options.

The most important option is the location --prefix where httpd is to be installed later, because httpd has to be configured for this location to work correctly. More fine-tuned control of the location of files is possible with additional configure options.

Also at this point, you can specify which features you want included in httpd by enabling and disabling modules. httpd comes with a wide range of modules included by default. They will be compiled as shared objects (DSOs) which can be loaded or unloaded at runtime. You can also choose to compile modules statically by using the option --enable-module=static.

Additional modules are enabled using the --enable-module option, where module is the name of the module with the mod_ string removed and with any underscore converted to a dash. Similarly, you can disable modules with the --disable-module option. Be careful when using these options, since configure cannot warn you if the module you specify does not exist; it will ignore the option.

In addition, it is sometimes necessary to provide the configure script with extra information about the location of your compiler, libraries, or header files. This is done by passing either environment variables or command line options to configure. For more information, see the configure manual page. Or invoke configure using the --help option.

For a short impression of what possibilities you have, here is a typical example which compiles httpd for the installation tree /sw/pkg/apache with a particular compiler and flags plus the two additional modules mod_ldap and mod_lua:

$ CC="pgcc" CFLAGS="-O2" \
  ./configure --prefix=/sw/pkg/apache \
  --enable-ldap=shared \
  --enable-lua=shared

When configure is run it will take several minutes to test for the availability of features on your system and build Makefiles which will later be used to compile the server.

Details on all the different configure options are available on the configure manual page.

Build ¶

Now you can build the various parts which form the httpd package by running:

$ make

Please be patient here, since a base configuration takes several minutes to compile and the time will vary widely depending on your hardware and the number of modules that you have enabled.

Install ¶

Now it's time to install the package under the configured installation PREFIX (see --prefix option above) by running:

$ make install

This step will typically require root privileges, since PREFIX is usually a directory with restricted write permissions.

If you are upgrading, the installation will not overwrite your configuration files or documents.

Customize ¶

Next, you can customize your Apache HTTP Server by editing the configuration files under PREFIX/conf/.

$ vi PREFIX/conf/httpd.conf

Have a look at the httpd manual under PREFIX/docs/manual/ or consult https://httpd.apache.org/docs/2.4/ for the most recent version of this manual and a complete reference of available configuration directives.

Test ¶

Now you can start your Apache HTTP Server by immediately running:

$ PREFIX/bin/apachectl -k start

You should then be able to request your first document via the URL http://localhost/. The web page you see is located under the DocumentRoot, which will usually be PREFIX/htdocs/. Then stop the server again by running:

$ PREFIX/bin/apachectl -k stop

Upgrading ¶

The first step in upgrading is to read the release announcement and the file CHANGES in the source distribution to find any changes that may affect your site. When changing between major releases (for example, from 2.4 to 2.6), there will likely be major differences in the compile-time and run-time configuration that will require manual adjustments. All modules will also need to be upgraded to accommodate changes in the module API.

Upgrading from one minor version to the next (for example, from 2.4.66 to 2.4.67) is easier. The make install process will not overwrite any of your existing documents, log files, or configuration files. In addition, the developers make every effort to avoid incompatible changes in the configure options, run-time configuration, or the module API between minor versions. In most cases you should be able to use an identical configure command line, an identical configuration file, and all of your modules should continue to work.

To upgrade across minor versions, start by finding the file config.nice in the build directory of your installed server or at the root of the source tree for your old install. This will contain the exact configure command line that you used to configure the source tree. Then to upgrade from one version to the next, you need only copy the config.nice file to the source tree of the new version, edit it to make any desired changes, and then run:

$ ./config.nice
$ make
$ make install
$ PREFIX/bin/apachectl -k graceful-stop
$ PREFIX/bin/apachectl -k start

You can pass additional arguments to config.nice, which will be appended to your original configure options:

$ ./config.nice --prefix=/home/test/apache --with-port=90

Third-party packages ¶

Many operating systems ship pre-built Apache httpd packages. These are convenient for getting started quickly, but they often differ from a source build in configuration file layout, compiled-in modules, and default paths. The documentation on this site describes the server as built from source; if you are using a platform package, consult your distribution's documentation for platform-specific details.

Some common examples:

Fedora / CentOS / Red Hat Enterprise Linux

sudo dnf install httpd
sudo systemctl start httpd

See the Fedora project's documentation for configuration layout and platform-specific notes.

Ubuntu / Debian

sudo apt install apache2
sudo systemctl start apache2

See Ubuntu's documentation for configuration layout and platform-specific notes.

Our software license not only permits, but encourages, this kind of redistribution. However, it does result in a situation where the configuration layout and defaults on your installation of the server may differ from what is stated in the documentation. A description of these third-party distributions is available in the HTTP Server wiki.