MediaWiki

MediaWiki is a free and open source wiki software written in PHP, originally developed for Wikipedia. It also powers this wiki (see Special:Version and the GitHub repository).

Installation

To run MediaWiki you need three things:

the mediawiki package, which pulls in PHP
a web server, such as Apache HTTP Server, nginx or lighttpd
a database system – one of MariaDB, PostgreSQL, SQLite or MySQL

To install MediaWiki on XAMPP, see mw:Manual:Installing MediaWiki on XAMPP

Configuration

The steps to achieve a working MediaWiki configuration involve editing the PHP settings and adding the MediaWiki configuration snippets.

PHP

MediaWiki requires the iconv and the intl extensions, so you need to uncomment extension=iconv and extension=intl in /etc/php/php.ini.

Optional dependencies:

For thumbnail rendering, install either ImageMagick or php-gd. If you choose the latter, you also need to uncomment extension=gd.

Enable the API for your DBMS:

If you use MariaDB, uncomment extension=mysqli.
If you use PostgreSQL, install php-pgsql and uncomment extension=pgsql.
If you use SQLite, install php-sqlite and uncomment extension=pdo_sqlite.

Second, tweak the session handling or you might get a fatal error (PHP Fatal error: session_start(): Failed to initialize storage module[...]) by finding the session.save_path path. A good choice can be /var/lib/php/sessions or /tmp/.

/etc/php/php.ini

session.save_path = "/var/lib/php/sessions"

You will need to create the directory if it does not exist and then restrict its permissions:

# mkdir -p /var/lib/php/sessions/
# chown http:http /var/lib/php/sessions
# chmod go-rwx /var/lib/php/sessions

If you use PHP's open_basedir and want to allow file uploads, you need to include /var/lib/mediawiki/ (mediawiki symlinks images/ to /var/lib/mediawiki/).

Web server

Apache

Follow Apache HTTP Server#PHP.

Copy /etc/webapps/mediawiki/apache.example.conf to /etc/httpd/conf/extra/mediawiki.conf and edit it as needed.

Add the following line to /etc/httpd/conf/httpd.conf:

Include conf/extra/mediawiki.conf

Restart the httpd.service daemon.

Note: The default file from /etc/webapps/mediawiki/apache.example.conf will overwrite the PHP open_basedir setting, possibly conflicting with other pages. This behavior can be changed by moving line starting with php_admin_value between the <Directory> tags. Further, if you are running multiple applications that depend on the same server, this value could also be added to the open_basedir value in /etc/php/php.ini instead of /etc/httpd/conf/extra/mediawiki.conf

Nginx

The factual accuracy of this article or section is disputed.

Reason: /mw-config/index.php should not be exposed, see Talk:MediaWiki#/mw-config/index.php is exposed with Nginx config. (Discuss in Talk:MediaWiki)

To get MediaWiki working with Nginx, create the following file:

/etc/nginx/mediawiki.conf

location / {
   index index.php;
   try_files $uri $uri/ @mediawiki;
}
location @mediawiki {
   rewrite ^/(.*)$ /index.php;
}
location ~ \.php$ {
   include /etc/nginx/fastcgi_params;
   fastcgi_pass unix:/var/run/php-fpm/php-fpm.sock;
   fastcgi_index index.php;
   fastcgi_param  SCRIPT_FILENAME  $document_root$fastcgi_script_name;
   try_files $uri @mediawiki;
}
location ~* \.(js|css|png|jpg|jpeg|gif|ico|svg)$ {
   try_files $uri /index.php;
   expires max;
   log_not_found off;
}
# Restrictions based on the .htaccess files
location ~ ^/(cache|includes|maintenance|languages|serialized|tests|images/deleted)/ {
   deny all;
}
location ~ ^/(bin|docs|extensions|includes|maintenance|mw-config|resources|serialized|tests)/ {
   internal;
}
location ^~ /images/ {
   try_files $uri /index.php;
}
location ~ /\. {
   access_log off;
   log_not_found off; 
   deny all;
}
location /rest.php {
   try_files $uri $uri/ /rest.php?$args;
}

Ensure that php-fpm is installed and php-fpm.service is started.

Include a server directive, similar to this

/etc/nginx/nginx.conf

server {
  listen 80;
  server_name mediawiki;
  root /usr/share/webapps/mediawiki;
  index index.php;
  charset utf-8;
# For correct file uploads
  client_max_body_size    100m; # Equal or more than upload_max_filesize in /etc/php/php.ini
  client_body_timeout     60;
  include mediawiki.conf;

}

Finally, restart nginx.service and php-fpm.service daemons.

Lighttpd

You should have Lighttpd installed and configured. "mod_alias" and "mod_rewrite" in server.modules array of lighttpd is required. Append to the lighttpd configuration file the following lines

/etc/lighttpd/lighttpd.conf

alias.url += ("/mediawiki" => "/usr/share/webapps/mediawiki/")
url.rewrite-once += (
                "^/mediawiki/wiki/upload/(.+)" => "/mediawiki/wiki/upload/$1",
                "^/mediawiki/wiki/$" => "/mediawiki/index.php",
                "^/mediawiki/wiki/([^?]*)(?:\?(.*))?" => "/mediawiki/index.php?title=$1&$2"
)

Restart the lighttpd.service daemon.

Database

Set up a database server as explained in the article of your DBMS: MariaDB, PostgreSQL, SQLite or MySQL.

If you have set a non-empty root password for the database server, MediaWiki can automatically create the database during the next step. (See MariaDB#Reset the root password for how to set this password retrospectively for MariaDB.) Otherwise the database needs to be created manually - see upstream instructions.

LocalSettings.php

Open the wiki URL (usually http://your_server/mediawiki/index.php) in a browser and do the initial configuration. Follow upstream instructions.

The generated LocalSettings.php file is offered for download, save it to /etc/webapps/mediawiki/LocalSettings.php.

Since 1.38.0 it has a symbolic link included in /usr/share/webapps/mediawiki/LocalSettings.php.

Warning: LocalSettings.php contains database connection settings, such as the usename and password, and the MediaWiki web-based updater password. Make sure only the root and http users have access to /etc/webapps/mediawiki/LocalSettings.php:

# chown root:http /etc/webapps/mediawiki/LocalSettings.php
# chmod 640 /etc/webapps/mediawiki/LocalSettings.php

This file defines the specific settings of your wiki. Whenever you upgrade the mediawiki package, it will not be replaced.

LDAP Auth

Use PluggableAuth and LDAP Stack. Pay attention to "Compatibility Matrix" section. Currently LDAP works only with PluggableAuth-5.7.

You need to install and add to config ldap stack extensions and PluggableAuth:

Then set up at least 3 variables:

$LDAPProviderDomainConfigProvider - whole ldap config (can be in json file)
$wgPluggableAuth_Config - list of auth plugins

$wgPluggableAuth_Config = array(
       array('plugin' => 'LDAPAuthentication2'),
       array('plugin' => 'LDAPAuthorization'),
);

and $LDAPProviderDefaultDomain

Do not forget to run php maintenance/update.php after configuration.

Upgrading

See mw:Manual:Upgrading, and do not forget to run:

# cd /usr/share/webapps/mediawiki
# php maintenance/update.php

Tips and tricks

Unicode

Check that PHP, Apache HTTP Server and MariaDB all use UTF-8. Otherwise you may face strange bugs because of encoding mismatch.

VisualEditor

The VisualEditor MediaWiki extension provides a rich-text editor for MediaWiki. Follow mw:Extension:VisualEditor to install it.