MediaWiki

MediaWiki is an opensource wiki engine written in PHP by the Wikimedia Foundation. It is used by both Wikipedia and this site.

Visit the project website at:

• https://www.mediawiki.org

Running inside Docker

You can run MediaWiki from a Docker container. A proof of concept can be found at:

• https://git.steamr.com/docker/mediawiki

Data that would need to be imported to support customizations would include:

1. Images / Uploads
2. Extensions
3. Skins
4. The LocalSettings.php configuration file
5. Database (on a remote server / container / microservice), or a SQLite file on a volume

Configuration

MediaWiki only has a single configuration file at LocalSettings.php.

Extensions

Extensions are placed under the /extensions directory. Common extensions are bundled with the base installation of MediaWiki but not enabled by default. Extentions that are bundled can be enabled by adding a wfLoadExtention('extention') call to the LocalSettings.php file.

However there are some that need to be added including:

Intersection

https://github.com/wikimedia/mediawiki-extensions-intersection.git

Generates dynamic lists

Scribunto

https://github.com/wikimedia/mediawiki-extensions-Scribunto.git

Generates scripted outputs using Lua

Math

https://extdist.wmflabs.org/dist/extensions/Math-REL1_30-e13d2d5.tar.gz

Generates math formulas

Skins

Skins are placed under the /skins directory. Modern skins are loaded with the wfLoadSkin('skin') call in LocalSettings.php, which reads the skin's skin.json manifest file in the skin's directory. The manifest file contains the skin's name, autoload class files, as well as which resource modules to load loaded, including the stylesheets and javascript files that are part of the skin.

MediaWiki's guide on skinning is relatively up to date albeit a little confusing to understand at first.

• https://www.mediawiki.org/wiki/Manual:Skinning_Part_2

The Reader skin used on this wiki:

• https://git.steamr.com/leo/mediawiki-reader-skin

Troubleshooting

Scribunto Lua Failures

If templates cause this error:

Lua error: Internal error: The interpreter exited with status 127.

This likely means that you do not have Lua installed or it is not in the PATH. You will need to specify the Lua path in LocalSettings.php with this line:

$wgScribuntoEngineConf['luastandalone']['luaPath'] = "/usr/bin/lua5.1";

Database Import Incomplete

Database imports from MySQL 5.7.27 to a MariaDB 10.4.7 seems to fail. Imports only appear to complete if the database dump was made without Enclose export in a transaction enabled in PHPMyAdmin but subsequent edits on the destination wiki will result in this error message:

The revision #0 of the page named "some-article" does not exist.

This is usually caused by following an outdated history link to a page that has been deleted. Details can be found in the deletion log.

Solution

It turns out the destination database server (mariadb:10.4.7, in docker) was not set up properly after being upgraded from MariaDB-10.1. On start up, it showed the following error messages:

2019-09-01 21:14:44 0 [Note] Server socket created on IP: '::'.
2019-09-01 21:14:44 0 [Warning] 'user' entry 'root@localhost.localdomain' ignored in --skip-name-resolve mode.
2019-09-01 21:14:44 0 [Warning] 'proxies_priv' entry '@% root@localhost.localdomain' ignored in --skip-name-resolve mode.
2019-09-01 21:14:44 0 [ERROR] Missing system table mysql.roles_mapping; please run mysql_upgrade to create it
2019-09-01 21:14:44 0 [ERROR] Incorrect definition of table mysql.event: expected column 'sql_mode' at position 14 to have type set('REAL_AS_FLOAT','PIPES_AS_CONCAT','ANSI_QUOTES','IGNORE_SPACE','IGNORE_BAD_TABLE_OPTIONS','ONLY_FULL_GROUP_BY','NO_UNSIGNED_SUBTRACTION','NO_DIR_IN_CREATE','POSTGRESQL','ORACLE','MSSQL','DB2','MAXDB','NO_KEY_OPTIONS','NO_TABLE_OPTIONS','NO_FIELD_OPTIONS','MYSQL323','MYSQL40','ANSI','NO_AUTO_VALUE_ON_ZERO','NO_BACKSLASH_ESCAPES','STRICT_TRANS_TABLES','STRICT_ALL_TABLES','NO_ZERO_IN_DATE','NO_ZERO_DATE','INVALID_DATES','ERROR_FOR_DIVISION_BY_ZERO','TRADITIONAL','NO_AUTO_CREATE_USER','HIGH_NOT_PRECEDENCE','NO_ENGINE_SUBSTITUTION','PAD_CHAR_TO_FULL_LENGTH','EMPTY_STRING_IS_NULL','SIMULTANEOUS_ASSIGNMENT'), found type set('REAL_AS_FLOAT','PIPES_AS_CONCAT','ANSI_QUOTES','IGNORE_SPACE','IGNORE_BAD_TABLE_OPTIONS','ONLY_FULL_GROUP_BY','NO_UNSIGNED_SUBTRACTION','NO_DIR_IN_CREATE','POSTGRESQL','ORACLE','MSSQL','DB2','MAXDB','NO_KEY_OPTIONS','NO_TABLE_OPTIONS','NO_FIELD_OPTIONS','MYSQL323','MYSQL40','ANSI','NO_AUTO_VALU
2019-09-01 21:14:44 0 [ERROR] mysqld: Event Scheduler: An error occurred when initializing system tables. Disabling the Event Scheduler.
2019-09-01 21:14:44 6 [Warning] Failed to load slave replication state from table mysql.gtid_slave_pos: 1146: Table 'mysql.gtid_slave_pos' doesn't exist
2019-09-01 21:14:44 0 [Note] Reading of all Master_info entries succeeded
2019-09-01 21:14:44 0 [Note] Added new Master_info '' to hash table
2019-09-01 21:14:44 0 [Note] mysqld: ready for connections.
Version: '10.4.7-MariaDB-1:10.4.7+maria~bionic'  socket: '/var/run/mysqld/mysqld.sock'  port: 3306  mariadb.org binary distribution
2019-09-01 21:14:46 0 [Note] InnoDB: Buffer pool(s) load completed at 190901 21:14:46
2019-09-01 21:14:49 8 [ERROR] InnoDB: Table `mysql`.`innodb_table_stats` not found.
2019-09-01 21:14:49 8 [ERROR] Transaction not registered for MariaDB 2PC, but transaction is active
2019-09-01 21:15:13 9 [ERROR] Transaction not registered for MariaDB 2PC, but transaction is active
2019-09-01 21:15:13 9 [ERROR] Transaction not registered for MariaDB 2PC, but transaction is active
2019-09-01 21:15:13 9 [ERROR] Transaction not registered for MariaDB 2PC, but transaction is active

Running mysql_upgrade fixed these errors and a subsequent database import was successful.

Math Extension

Using the latest Math extension, formulas constantly return errors similar to:

Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle V=IR}

I installed Mathoid and tried to set the $wgMathFullRestbaseURL to the service to no avail since $wgMathFullRestbaseURL required the Restbase API rather than the Mathoid API. I did not want to install Restbase for a simple wiki and requiring Restbase will make hosting it on a shared hosting environment tricky.

Solution

It turns out that the Math extension versions 1.30 and prior works. $ E=mc^{2} $