User:Aeric/Background Information

How the Wiki Works

• Mediawiki consists of a database and a bunch of PHP scripts and supporting files in the Wiki directory.
• The actual Wiki content is contained in a database.
• Together, the file set and the database make up the Wiki that user sees.
• In addition to PHP scripts, the directory contains:

  LocalSettings.php

  The master control script where everything else is configured.

  skins/

  The images and CSS files that create the "wrapper context" (headers, nav pane, etc.) for the wiki content.

  extensions/

  MediaWiki plug-ins that have been downloaded and "installed" by referencing them in LocalSettings.php. (Since pages are loaded dynamically, once the extension is present, it is automatically part of the Wiki. No restart needed.)

  images/

  A directory hierarchy that contains the image files after they have been loaded. The Wiki stores them there when you load an image, and keeps a pointer to them in the database.

  image-files/

  A directory we create on the local file system. It contains images that will be (or have been) uploaded to the wiki. The Wiki doesn't know about this directory. It's just a place where images can be saved before uploading. The backup system re-creates this directory from the images/ file, so that an entire working environment is restored.

  download/

  A directory we added to hold files we want to reference in the wiki. Only image files can be loaded into the Wiki. But that's ok. Image loads are done painfully, one at a time. Files in the download/ folder can be easily updated en mass. (Image files need to be uploaded, so that "links" to them coded in the wiki cause the image to be displayed, rather than link text.)

Wiki/Server Configuration Notes

• The wiki is hosted at Racksace. The site name is "platformatyourservice.com".
• Location is /usr/share/mediawiki/{wiki_name}
• Multiple subdomains are set up using Apache, the DNS server, and LocalSettings.php.
• The DNS server forwards platformatyourservice.com -> isv.platformatyourservice
• The Wiki examines the server name (which includes the subdomain) to determine which logos to show and which platform name to use:
  • In {wiki_name}/LocalSettings.php, $wgSitename declares the name of the Wiki site.
  • That value is set conditionally, based on the subsomain used to access the PHP page.
  • So the same verison of the Wiki is launched in all three cases, but LocalSettings.php changes $wgSitename depending on the subdomain used to access it.
  • When that variable's value is "ISV Support Wiki", the unbranded, ISV version of the wiki pages are shown. Otherwise, a logo and platform name appears.

Accessing the Server

The server can be accessed with a VPN connection, using either FTP or SSH. FTP gives access to all of the Wiki files, which is generally sufficient. (Details in emails.)

Apache Modifications

To modify the Apache configuration in /etc/httpd/conf.d/mediawiki.conf, either:

1. SSH to the server using PuTTY or the SSH shell, and use a line-oriented editor like nano.
2. Set up TightVnc and use it to run a darn good editor like Nedit.

Apache References

• http://net.tutsplus.com/tutorials/other/a-deeper-look-at-mod_rewrite-for-apache/
• http://www.addedbytes.com/download/regular-expressions-cheat-sheet-v2/png
• http://www.addedbytes.com/cheat-sheets/mod_rewrite-cheat-sheet/

Backup Notes

• A MediaWiki site contains a number of wiki files and a database.
• The Wiki content files are in the images/, extensions/, and download/ folders, plus some other files.
• Each Wiki has its own database.
  The database contains page contents and edit history. It is created when the wiki is set up. Data is exported using mysqldump, and imported using mysql.

Branching Notes

• The sandbox is the new wiki you are creating. There is (or will be) a local copy on your system, as well as the remote copy on the server.