---
Installing MediaWiki
---

Starting with MediaWiki 1.2.0, it's possible to install
and configure the wiki "in-place", as long as you have
the necessary prerequesites available.

Required software:
* Web server with PHP 4.1.2 or higher (4.3.x is preferred)
* A MySQL server. 4.0.x is preferred, but 3.2.x should
  work as well.

MediaWiki is developed and tested mainly on Unix/Linux
platforms, but should work on Windows as well.

If your PHP is configured as a CGI plug-in rather than
an Apache module you may experience problems, as this
configuration is not well tested.

Don't forget to check the RELEASE-NOTES file...

********************** WARNING **************************

The web-based install is still somewhat experimental. It
doesn't yet support updating the format of an existing
MediaWiki database, the maintenance scripts aren't available,
and there may be all kinds of horrible bugs or security
problems that haven't been worked out yet.

HOWEVER it is much easier, safer, and more reliable than
the old install.php, and does not require root access
if you already have a database and user access to it.

REMEMBER: ALWAYS BACK UP YOUR DATABASE BEFORE ATTEMPTING
TO INSTALL OR UPGRADE!!!

----
In-place web install
----

Decompress the MediaWiki installation archive either on
your server, or on your local machine and upload the
directory tree. Rename it from "mediawiki-1.x.x" to
something nice, like "wiki", since it'll be in your URL.

To run the install script, you'll need to temporarily make
the 'config' subdirectory writable by the web server. The
simplest way to do this on a Unix/Linux system is to make
it world-writable:

  chmod a+w config

Hop into your browser and surf into the wiki directory.
It'll direct you into the config script. Fill out the form...
remember you're probably not on an encrypted connection.
Gaaah! :)

If all goes well, you should soon be told that it's set up
your wiki database and written a configuration file. There
should now be a 'LocalSettings.php' in the config directory;
move it back up to the main wiki directory, and the wiki
should now be working.

Once the wiki is set up, you should remove the config
directory, or at least make it not world-writable (though
it will refuse to config again if the wiki is set up).


----
"Classic" install instructions:
----

THE INSTRUCTIONS BELOW ARE OLD AND MAY BE INACCURATE.
THIS INSTALL METHOD IS NOT RECOMMENDED, IT MAY RUN
OVER YOUR DOG.

If you use the command-line install, you MUST NOT make the
source directory web-accessible, as it will expose maintenance
scripts to the public internet. You MUST NOT install to the
same directory as your are installing from, this WILL
overwrite and destroy files.

Because install.php and update.php are unsafe, they have
been disabled as of 1.2.4. If you wish to use them, remove
the "die()" call at the top of the file.

--

The Wikipedia software was developed collaboratively by
many people, so it's something of a hodgepodge. The
main wiki software itself is written in PHP, and requires
the Apache web server and MySQL database. The optional
math rendering functions are written in Objective CAML,
which is required to compile them.

Recommended versions are: Apache 1.3.27 or later; MySQL
4.0.13 or later; PHP 4.3.2 or later. The installation at
wikipedia.org also uses PHP Accelerator software, but
that's entirely optional and doesn't affect anything else.

The math rendering functions are more complex, and will
probably only work on Linux. Objective CAML (probably
3.06 or later) is required to compile texvc, but produces
static binaries. TeTeX and ImageMagick are required at
runtime, and ImageMagick requires GhostScript. These are
present in most Linux distributions.

----
Scripts install.php and update.php
----

Before installing the software, you must copy the file
"LocalSettings.sample" to "LocalSettings.php", and
"AdminSettings.sample" to "AdminSettings.php", and
customize both of the php files to your local setup
(things like installation path, passwords, etc.) The
script install.php can then be run to install the
software. It must be run from the command line with
PHP: that is, type "php install.php" (you may need to
specify the path the php executable). You will probably
need to run as root.

 Hint: If you are using Debian, the PHP interpreter is 
 not part of the "php4" package; you need to install
 php4-cgi separately (the interpreter will be called 
 php4).

This script will copy all the necessary software over to
the directories you have specified in the settings files.
It will then warn you that it is about to create the
database and give you the chance to exit. If you are
installing the software to an existing database, you can
answer "no" here and it will be left alone. The software
installation will be otherwise complete. If you do choose
to create a new database, you will need te root password
to your MySQL installation.

If you are merely updating an existing installation, run
"php update.php" instead of install.  This will copy all
the software, and also run any database updates that may
be necessary. These should give appropriate warnings if
there are any dangerous ones.

----
Building from scratch
----

Here are some more notes on building a system from scratch
the way it was done for the Wikipedia server:

Downloads:

  gcc-2.95.3.tar.gz (only if you now have gcc 2.96)
  mysql-4.0.13.tar.gz (or 3.23.57 should work)
  libiconv-1.8.tar.gz
  apache_1.3.27.tar.gz
  php-4.3.2.tar.gz
  apc-cvs.tar.gz

And for math support:
  ocaml-3.06.tar.gz (3.04 doesn't work)
  (TeTeX, ImageMagick, and GhostScript come with most Linux distros)

1. MySQL strongly recommends using gcc 2.95 to compile MySQL.
  RedHat Linux 7.x comes with 2.96 by default, so you'll have to install
  2.95 first.  Use "../gcc*/configure --enable-shared"  If your Linux
  installation doesn't use gcc 2.96, or has a more recent gcc 3.x,
  you can skip this step.

2. Install MySQL source; add "mysql" user and group. Make sure the
  directory into which you installed gcc 2.95 appears before the
  directory of gcc 2.96 in your path.  Configure with:

  FLAGS="-O3 -mcpu=i686" CXX=gcc CXXFLAGS="-O3 -mcpu=i686 -felide-constructors -fno-exceptions -fno-rtti" ./configure --prefix=/usr/local/mysql --enable-assembler --with-mysqld-ldflags=-all-static --disable-shared --with-extra-charset=complex

  Edit the file myisam/ftdefs.h, changing the define for minimum word
  length for fulltext indexing: #define MIN_WORD_LEN 2.  Update
  $wgDBminWordLen in LocalSettings.php to reflect this.  Build and
  install according to instructions.  Make root user as recommended;
  the root password will be required for the wiki installation script.

3. Unpack the phase3.zip source distribution, or check out the "phase3"
  module from CVS. Copy LocalSettings.sample to LocalSettings.php,
  AdminSettings.sample to AdminSettings.php, and customize them for
  things like local paths and passwords.  If desired, update
  FulltextStoplist.php from the MySQL sources if you have customized
  MySQL's stop list.

  If you are running anything other than Wikipedia itself you'll want
  to make a lot of changes to the LanguageXX.php files so it talks about
  _your_ site and _your_ license. :)

4. Optionally, install libiconv (http://www.gnu.org/software/libiconv/).
  This will be used by some language packages for converting
  native-charset URLs to and from UTF-8. If you're running an
  English-only wiki, this probably won't be necessary. (Most Linux
  distributions should come with libiconv anyway, but check for
  a separate 'dev' package if on RedHat.)

5. Unpack Apache distribution and begin configuring, but don't finish
  build yet. Configure with something like:

   OPTIM='-O2 -mcpu=i686' ./configure --with-layout=Apache

6. If you'll want to use Apache's mod_rewrite to make page-viewing URLs
  look like static links (as wikipedia.org does), install the included
  patch "apache-ampersand.diff" which is needed to support page titles
  with ampersands in them:

   patch -p0 < /path/to/maintenance/apache-ampersand.diff

7. Unpack and configure PHP. Configure with something like:

  ./configure --enable-shmop --with-zlib --with-zlib-dir=/usr/lib --with-mysql=/usr/local/mysql --with-iconv --with-apache=/home/lee/src/apache_1.3.26 --with-readline --enable-sockets

Or for Apache 2.0 module:
  ./configure --enable-shmop --with-zlib --with-zlib-dir=/usr/lib --with-mysql=/usr/local/mysql --with-iconv --with-apxs2filter=/usr/local/apache/bin/apxs --with-readline --enable-sockets

  (using your own local paths, of course). Build and install as
  instructed.

8. Finish building Apache. Configure with something like:

  OPTIM='-O2 -mcpu=i686' ./configure --with-layout=Apache --enable-module=rewrite --enable-module=mmap-static --enable-module=headers --enable-module=expires --activate-module=src/modules/php4/libphp4.a

  Update httpd.conf as needed for your site.  For example:

  <IfModule mod_php4.c>
    AddType application/x-httpd-php .php .php4
    AddType application/x-httpd-php-source .phps
  </IfModule>
  <IfModule mod_php4.c>
    php_admin_flag engine off
  </IfModule>
  <Directory "DIRECTORY_OF_WIKI_SCRIPTS">
    <IfModule mod_php4.c>
      php_admin_flag engine on
    </IfModule>
  </Directory>
  RewriteEngine On
  RewriteMap ampescape int:ampescape
  RewriteRule ^/wiki/(.*)$ /index.php?title=${ampescape:$1} [L]

  It is *seriously* recommended that you configure the webserver
  to disable running of PHP scripts except in the script directories
  (the "php_admin_flag engine off/on" directives above) to prevent
  the uploading and running of malicious scripts.

9. Optionally, install APC or another PHP cache plug-in, following
  standard instructions for installing as a Zend extension.

10. If using embedded TeX support, be sure TeX and ImageMagick are
  installed (they are common on most Linux distros and freely
  downloadable). Also get and install OCaml according to its
  instructions.

  You'll need to compile the texvc helper script; enter the math
  subdirectory of the source tree and run "make".

  If you want embedded TeX support, enable it by setting

   $wgUseTex = true;

  in LocalSettings.php

11. You should now be able to run the install.php script. Use PHP in
  command-line mode, i.e., type "php install.php". Should be run as
  root, or as a user or group able to create files and directories
  in the installation tree.

12. If you have Java installed and running, install the "ant" package
  from Apache (http://ant.apache.org/) and run ant in the testsuite
  directory to build the tests. Copy wikitest.prefs.sample to
  wikitest.prefs, and edit to reflect your local settings.  Then
  "./run WikiSuite -o -b" will run the whole test suite and report.

----

Don't forget that this is pre-release software under development!
Chances are good there's a crucial step that hasn't made it
into the documentation. You should probably sign up for the
Wikipedia developers' mailing list; you can ask for help (please
provide enough information to work with, and preferably be aware
of what you're doing!) and keep track of major changes to the
software, including performance improvements and security patches.

http://mail.wikipedia.org/mailman/listinfo/wikitech-l