MediaWiki

I'm using the MediaWiki software from the WikiMedia Foundation to power my wikis. MediaWiki is written in PHP5, and thus precludes the use of a multi-threaded version of Apache.

Installing MediaWiki

The following information is largely Debian-specific.

• Have handy the administrator account/password for your MySQL installation.
  • I advise you to install MySQL before MediaWiki, not as a single apt step.
  • DO NOT explicitly create the MediaWiki databases / users yourself.
• Grab the necessary packages:
  • mediawiki and mediawiki-math; mediawiki-extensions is also advised.
  • In addition, memcached, imagemagick and tetex-base should be installed if they're not automatically dragged in.
• Don't grab the versioned packages (ie mediawiki1.10); the mediawiki package will depend on the proper packages for your version of Debian.
  • Unless you really need a particular version.
  • If you install the versioned packages explicitly, upgrades might eat your configuration. You have been warned.
• Symlink /var/lib/mediawiki to /var/www/mediawiki with ln -s.
  • This isn't in the install docs, and might be incorrect/suboptimal FIXME.
• Go to http://yourhost/mediawiki. You should be greeted with a link to the config page. Follow it.
• Configure that bitch (See Accelerators below).
  • I've seen no problems related to the experimental UTF-8 encoding for use with MySQL 5.0.
• Following configuration, run chmod 640 /var/lib/mediawiki/config/LocalSettings.php && ln -sf /var/lib/mediawiki/config/LocalSettings.php /etc/mediawiki
• Go to http://yourhost/mediawiki. You should be greeted with your new main page.

Accelerators

• MediaWiki: kinda slow.
• XCache is rumoured to be the best choice.
  • On Debian, you'll need edit the default /etc/php5/xcache.ini to provide non-0 size values
• memcached works out of the box, but doesn't seem very effective
  • You want the memcache server at 127.0.0.1:11211
• Ensure mod_deflate's compressing standard html/xml etc, and also application/x-javascript and text/css

Postinstallation

• Install help pages using Import/Export.
  • They require the ParserFunctions extension. Be sure to get the proper version for your MediaWiki install.
• Set a wiki logo: sudoedit /etc/mediawiki/LocalSettings.php and add
  • $wgLogo = "/mediawiki/skins/common/images/wiki.jpg"; with the appropriate path to your logo
  • Be sure the image is world-readable, 135x135 and has a correct extension
  • The path is relative to your Apache's configured DocumentRoot
  • If applicable, set the image background transparent so it'll look better
    • Using the Gimp, add an Alpha layer, select the background with the Magic Wand, and Clear it
• Support inline equations: sudoedit /etc/mediawiki/LocalSettings.php and change
  • $wgUseTeX = false; so that it uses true instead
  • The texex-bin package must be installed for this to work!
• Disable editing unless logged in: sudoedit /etc/mediawiki/LocalSettings.php and add
  • $wgGroupPermissions['*']['edit'] = false;
• Disable per-IP pages:sudoedit /etc/mediawiki/LocalSettings.php and add
  • $wgShowIPinHeader = false;
• Optionally, disable new accounts unless logged in: sudoedit /etc/mediawiki/LocalSettings.php and add
  • $wgGroupPermissions['*']['createaccount'] = false;
• Optionally, rename the main page: first, move the main page to the new title
  • Load Mediawiki:mainpage, and update it to reflect this change
• Optionally, remove the 'discussion' tab:
  • Edit MediaWiki:Common.css, and add the following:#ca-talk { display:none!important; }
  • Ensure $wgUseSiteCss=true in LocalSettings.php

Managing Uploads

• Enable uploads: sudoedit /etc/mediawiki/LocalSettings.php and add
  • $wgEnableUploads = true;
• Support uploading non-images: sudoedit /etc/mediawiki/LocalSettings.php and add

  • $wgFileExtensions = array( 'png', 'gif', 'jpg', 'jpeg', 'doc', 'pdf', 'ps', 'xls', 'txt', 'svg' );

  • Supposedly, all types can be allowed via:

 $wgCheckFileExtensions = false;
 $wgStrictFileExtensions = false;
 $wgVerifyMimeType = false;
 $wgFileBlacklist = array();
 $wgMimeTypeBlacklist= array();

• To allow files larger than the default 2M to be uploaded, edit the value of upload_max_filesize in /etc/php.ini
  • This requires a web server restart to take effect

Moving a wiki

There's a manual entry on this. My notes follow:

• The uploaded files are not stored in your database, and need be copied by themselves
  • By default, this is the 'images' directory off your wiki toplevel
  • Use a copying method that preserves timestamps, such as tar
• Be sure you grab your configuration files, particularly /etc/mediawiki/LocalSettings.php
• You will also likely want to transfer your web server config as it relates to the wiki
• If you're using Mediawiki account permissions only, they'll be stored in your wiki database
  • Otherwise, you'll of course need to copy over and prepare this supporting infrastructure
• Export your database with mysqldump as explained in the manual, and import it on the new machine
• If you can't do a database dump/load, you can do an XML export of all your pages
  • This won't copy things like account data!

Maintenance

• The MediaWiki manual has good information scattered through it; check the system administration page for sure
• Most everything can be done via the Special Pages page; learn it
• Check the Special:Lonelypages list to watch for orphaned pages; these pages are unreachable from any other page.
  • This almost always indicates a mistyped or misspelled attempt to link to this page; check the Special:Wantedpages list
• Check the Special:Deadendpages list to watch for dead-end pages; these pages link to no other pages.
  • This almost always indicated a failure to add a relevant link, or a short entry (see below)
• Check the Special:Shortpages list to watch for short pages; these pages might need more information.
  • See if the page can't be combined with another one, or if more info isn't sensible to add
• How to check for dead external links? FIXME
• Use the generateSitemap.php maintenance script to generate sitemaps; these can be registered with search services.

Extensions

A variety of extensions are available for MediaWiki. The most popular and stable are collected in the Debian package mediawiki-extensions, including (as of 1.10) GeSHi, Cite, inputbox, and ParserFunctions. By default, none are enabled -- the package only provides the extensions; it does not enable them!

Enabling Debian-Supported Extensions

• Install the mediawiki-extensions package.
• Enter the /etc/mediawiki-extensions/extensions-enabled directory.
• Enable extensions by creating symbolic links to contents of the /etc/mediawiki-extensions/extensions-available directory.
  • To enable all extensions, run: for i in ../extensions-available/* ; do sudo ln -s /etc/mediawiki-extensions/extensions-available/`basename $i` . ; done

Enabling other Extensions

• Download the extension to /var/lib/mediawiki/extensions
• See /var/lib/mediawiki/extensions/README for up-to-date information on enabling it
• Worth noting: googleAnalytics, Countdown, RSSNews

Editing

Wikipedia's tutorials and the Mediawiki help pages are the best references here:

• Wikipedia image tutorial

I also have some information.

Editing permissions

Some editing capabilities are by default disabled even for sysops:

$wgGroupPermissions['sysop']['deleterevision']  = true;
$wgGroupPermissions['sysop']['editsitecss']  = true;
$wgGroupPermissions['sysop']['editsitejs']  = true;

See Also

• mod_deflate configuration for Debian