MediaWikiLite

From Organic Design wiki
Revision as of 09:27, 29 May 2010 by Nad (talk | contribs) (Portable folder structure)

The idea of MediaWikiLite is to allow the current MediaWiki codebase to run as a standalone server without requiring a database server or web-server. This forms the foundation for a number of alternative uses for the MediaWiki software in environments where the current LAMP architecture is too resource intensive.

There are a number of personal desktop wiki's out there, but they do not use the MediaWiki parser, and making a fork of the parser code defeats the purpose. Also, embedded devices such as PDA's, iPod's and iPhone's can only run lite applications effectively and getting MediaWiki onto them would be very useful, especially if it could synchronise with a web-based mirror when an internet connection becomes available.

A lite version of MediaWiki would make a possible candidate for a client side wiki interface to a P2P article space, i.e. a decentralised Wikipedia or PeerPedia.

Removing the web and database servers

As of version 1.13, MediaWiki natively supports the SQLite database which is a program library compiled in to PHP instead of running as a separate server outside of the PHP environment. A running instance of MediaWiki 1.15.1 using the SQLite database can be seen at mediawikilite.org to test the current functionality.

To remove the need of an external web-server such as Apache or IIS, we're using NanoWeb which is a web-server entirely written entirely in PHP and comes with a number of modules such as a mod-rewrite clone for friendly URL's. It can execute CGI scripts using a normal CGI module or a FastCGI module.

Portable folder structure

I've packaged PHP/SQLite, NanoWeb and MediaWiki together into a self-contained folder structure which can be downloaded from here. The wiki is started by running the wiki.bat file in the base of this structure. Currently it only runs in Win32 environments, but soon the one structure will be able to be moved between Linux, OS X and Windows. Here's a tree view showing the main items in the structure:

Running multiple wiki's

Since there could be any number of these portable-wiki-folders we'd often want to run a number of them at once, but it would not be efficient or practical to have multiple instances of the NanoWeb server running on different ports, especially since they all use similarly named DLL's. It would be better if the wiki startup script were able to detect if an instance of NanoWeb were already running and if so create a new virtual host entry in the existing instance for the new wiki.

Debian package

For Debian and Ubuntu based Linux users, I'm creating a deb package to install the trio, it will be installed as follows:

echo "deb http://packages.organicdesign.co.nz main/" >> /etc/apt/sources.list
apt-get update
apt-get install organicdesign-nanowiki

Development notes

SQLite Installation

Currently we don't have a self-contained folder structure that MediaWikiLite's can run out of, so you'll need to ensure that SQLite is installed into the PHP environment properly. It's important to use SQLite3 rather than 2 because the former supports more similar syntax for some SQL such as table creation. Aside from that, version 3 uses more compact files and executes more efficiently because it works via PHP's PDO functions.

  • To install SQLite3 on a Debian based system, use apt-get install php5-sqlite3.
  • Check your phpinfo() to see if pdo_sqlite is listed, if not, try adding extension=php_pdo_sqlite.so into the dynamic extensions section of your php.ini

Running one Windows without installation

I've successfully created a self-contained folder structure containing NanoWeb and PHP which is able to be run from the command line without any changes to the OS. My test folder structure was C:\MyWiki and required config files to be created for both applications which I placed into the root of each (C:\MyWiki\nanoweb and C:\MyWiki\php). In the case of php.ini the only change required was to enable some extensions as follows:

extension_dir = ./php/ext

    .
    .
    .

extension=php_pdo.dll
extension=php_pdo_sqlite.dll
extension=php_sockets.dll


The NanoWeb configuration is a minimal file based on the nanoweb-win.conf sample that ships with it, and required numerous absolute path definitions so the startup script will need to create the nanoweb.conf configuration at runtime. Here's the successful configuration:

ServerMode        = standalone
SingleProcessMode = 1
ListenInterface   = 0.0.0.0
ListenPort        = 80
ListenQueue       = 20

ConfigDir         = c:\MyWiki\nanoweb\conf
TempDir           = c:\MyWiki\nanoweb\tmp
PidFile           = c:\MyWiki\nanoweb\nanoweb.pid
MimeTypes         = c:\MyWiki\nanoweb\conf\mime.types
ServerLog         = c:\MyWiki\nanoweb\log\server.log default
ServerLog         = c:\MyWiki\nanoweb\log\error.log warning+error
LogDir            = c:\MyWiki\nanoweb\log
Log               = access.log
LoggerProcess     = 0

DocumentRoot      = c:\MyWiki\mediawiki
DirectoryIndex    = index.php

KeepAlive         = 0
RequestTimeout    = 15
ChildLifeTime     = 21600

DefaultContentType = text/plain
HostnameLookups   = 1
HostnameLookupsBy = server
LoadTheme         = default.theme
ServerTheme       = default
ServerName        = localhost
ServerAdmin       = root@localhost
ServerSignature   = min

DefaultHandler    = static
ParseExt          = php CGI c:\MyWiki\php\php-cgi.exe
ParseExt          = exe CGI $SCRIPT_FILENAME
IgnoreDotFiles    = 1
AllowPathInfo     = 1
PathInfoTryExt    = php

ModulesDir        = C:\MyWiki\nanoweb\modules\
LoadModule        = mod_static.php
LoadModule        = mod_cgi.php

LoadModule        = mod_load_limit.php
LoadLimit         = 8.0
LoadLimitAction   = error
LoadLimitError    = 503
LoadLimitErrorMessage = Server load is too high (<b>%CUR_LOAD/%MAX_LOAD</b>), try again in a few moments.

LoadModule        = mod_pfilters.php
FilterEnable      = 1

LoadModule        = mod_gzip.php
GzipMaxRatio      = 90
GzipLevel         = 5


The command to then run NanoWeb from this structure was as follows:

php\php.exe sys\cwd.php > %TMP%\cwd.bat
call %TMP%\cwd.bat
call sys\make-conf.bat
start "%programfiles%\Internet Explorer\iexplore.exe" "%CD%\sys\splash.html"
php\php.exe -f %CD%\nanoweb\src\nanoweb.php -- --config=%TMP%\nanoweb.conf


The script first runs a small PHP script called cwd.php which sets the CWD to the base of the portable structure. On important aspect of this script is that it sets it in the old DOS 8.3 path format because the modules directive in nanoweb.conf can't handle spaces even when the value is double-quoted. The cwd.php script uses the SetSFN.exe utility to obtain the 8.3 name. Here's a listing of cwd.php:

{{{1}}}


The wiki.bat script then calls a second script called make-conf.bat which creates a nanoweb.conf file in the systems %TMP% directory. This step needs to be done because the NanoWeb configuration requires absolute file locations, the script is able to use a file-template based on the configuration shown above and replace all the file paths with the %CD%.

Wiki.bat then starts up a browser loaded with an HTML page called splash.html which is designed to redirect to the wiki main page after a few seconds to give NanoWeb a chance to start up. Launching NanoWeb is the last thing the wiki.bat script does and this command doesn't return until the command window is closed which shuts the web server down.

Issues

  • It often locks up when saving an article, restarting it shows that the save had worked though.
  • On intial install of the MediaWiki I got the following notice: Use of undefined constant SQLITE_SCHEMA - assumed 'SQLITE_SCHEMA' in C:\MyWiki\mediawiki\includes\db\DatabaseSqlite.php on line 302

What it looks like

Here's the proof of it working on my Virtual XP!!! (that I'm allowed to use due to the COA sticker on my computer)

Win32nanowiki.jpg

See also