Compiling and Installing
This document covers compilation and installation of Apache on Unix and Unix-like systems only. For compiling and installation on Windows, see Using Apache with Microsoft Windows. For other platforms, see the platform documentation.
Apache 2.0's configuration and installation environment has
changed completely from Apache 1.3. Apache 1.3 used a custom
set of scripts to achieve easy installation. Apache 2.0 now
uses libtool
and autoconf
to create an environment that looks like many other Open Source
projects.
If you are upgrading from one minor version to the next (for example, 2.0.50 to 2.0.51), please skip down to the upgrading section.
Overview for the impatient
Download | $ lynx http://httpd.apache.org/download.cgi
|
Extract | $ gzip -d httpd-2_0_NN.tar.gz |
Configure | $ ./configure --prefix=PREFIX
|
Compile | $ make |
Install | $ make install |
Customize | $ vi PREFIX/conf/httpd.conf |
Test | $ PREFIX/bin/apachectl start
|
NN must be replaced with the current minor 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 Apache:
- Disk Space
- Make sure you have at least 50 MB of temporary free disk space available. After installation Apache occupies approximately 10 MB of disk space. The actual disk space requirements will vary considerably based on your chosen configuration options and any third-party modules.
- 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 (version 2.7.2 is fine). 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 asmake
. - Accurate time keeping
- Elements of the HTTP protocol are expressed as the time of
day. So, it's time to investigate setting some time
synchronization facility on your system. Usually the
ntpdate
orxntpd
programs are used for this purpose which are based on the Network Time Protocol (NTP). See the Usenet newsgroup comp.protocols.time.ntp and the NTP homepage for more details about NTP software and public time servers. - Perl 5 [OPTIONAL]
- For some of the support scripts like
apxs
ordbmmanage
(which are written in Perl) the Perl 5 interpreter is required (versions 5.003 or newer are sufficient). If you have multiple Perl interpreters (for example, a systemwide install of Perl 4, and your own install of Perl 5), you are advised to use the--with-perl
option (see below) to make sure the correct one is used byconfigure
. If no Perl 5 interpreter is found by theconfigure
script, you will not be able to use the affected support scripts. Of course, you will still be able to build and use Apache 2.0.
Download
Apache can be downloaded from the Apache HTTP Server
download site which lists several mirrors. Most users of
Apache on unix-like systems will be better off downloading and
compiling a source version. The build process (described below) is
easy, and it allows you to customize your server to suit your needs.
In addition, binary releases are often not up to date with the latest
source releases. If you do download a binary, follow the instructions
in the INSTALL.bindist
file inside the distribution.
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 download page and an extended example is available describing the use of PGP.
Extract
Extracting the source from the Apache HTTPD tarball is a simple matter of uncompressing, and then untarring:
$ gzip -d httpd-2_0_NN.tar.gz
$ tar xvf httpd-2_0_NN.tar
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 Apache 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
the CVS version of the Apache 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,
simply 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 Apache is to be installed later, because Apache 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 Apache by enabling and disabling modules. Apache comes with a Base set of modules included by
default. Other 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. You can also choose to compile modules as shared objects (DSOs) -- which can be loaded
or unloaded at runtime -- by using the option
--enable-module=shared
. Similarly, you can
disable Base 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 simply 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.
For a short impression of what possibilities you have, here
is a typical example which compiles Apache for the installation
tree /sw/pkg/apache
with a particular compiler and flags
plus the two additional modules mod_rewrite
and
mod_speling
for
later loading through the DSO mechanism:
$ CC="pgcc" CFLAGS="-O2" \
./configure --prefix=/sw/pkg/apache \
--enable-rewrite=shared \
--enable-speling=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 Apache package by simply running the command:
$ make
Please be patient here, since a base configuration takes approximately 3 minutes to compile under a Pentium III/Linux 2.2 system, but this will vary widely depending on your hardware and the number of modules which 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
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 Apache manual under docs/manual/ or consult http://httpd.apache.org/docs/2.0/ 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 start
and then you should be able to request your first document
via 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 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 1.3 to 2.0 or from 2.0 to 2.2),
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 accomodate changes in the
module API.
Upgrading from one minor version to the next (for example, from
2.0.55 to 2.0.57) 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. (This is only valid for versions after 2.0.41; earlier
versions have incompatible changes.)
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 stop
$ PREFIX/bin/apachectl start
--prefix
and a
different port (by adjusting the Listen
directive) to test for any
incompatibilities before doing the final upgrade.