Editing IT Wiki (section)

==Configuration==

===VisualEditor installation===
VisualEditor is a MediaWiki extension written in PHP.  It is located in <code>/var/www/html/extensions</code>.  MediaWiki's configuration file is <code>/var/www/html/LocalSettings.php</code>.  MediaWiki has been configured to load VisualEditor, and to access the Parsoid via http://localhost:8000.  VisualEditor is not loaded by default for each user.  They must elect to edit with Visual Editor.

It requires Parsoid, a Node.js package.  Node.js runs independently of Apache.  The VisualEditor uses an API via HTTP on port 8000 to interact with Parsoid.  This traffic is not encrypted because it does not leave the host.  Parsoid's configuration file is located at <code>/usr/local/lib/node_modules/parsoid/config.yaml</code>.  It is copied from the default packaged configuration at config-example.yaml.  

The CES wiki API is not at the default address, https://ces-wiki.fas.harvard.edu/w/api.php.  The Parsoid configuration has been updated to reflect the correct address, [[Api.php|https://ces-wiki.fas.harvard.edu/api.php]].  Because the wiki is private, Parsoid cannot access the wiki API without a password.  Permissions have been updated to be public for the localhost and private for the rest of the world.  It does not test for the literal "localhost" but rather the server's IP address, 192.241.158.155.  

MediaWiki was updated to 1.33 because VisualEditor was not compatible with 1.30.

To start Parsoid, navigate to <code>/usr/local/lib/node_modules/parsoid</code>, and run <code>npm start</code>.  This process will end as soon as the terminal is closed, causing VisualEditor to fail to load.

===PM2===
To run Parsoid as a daemon, the Node.js package pm2 was installed.  To start Parsoid as a service, run the following:

<code>pm2 start /usr/local/lib/node_modules/parsoid/bin/server.js</code>

===Backing up the databases===
The databases can be backed up using the following command:

<code>mysqldump --all-databases > ~/Backups/$(date +%F)_wiki_db_backup.sql</code>

Backups are stored in <code>/home/peterstevens/Backups</code>.  Old backups do not clear out.  Additionally, DigitalOcean backs up the entire server image once a week.

===Updating MediaWiki===
Always back up the database and the image assets before updating.  MediaWiki can be updated by creating new directory <code>/var/www/html_upgrade</code> and unzipping the latest copy of MediaWiki there.  Then, copy the following files and directories from <code>/var/www/html</code>:

*<code>LocalSettings.php</code>
*<code>images</code>
*<code>skins</code>
*<code>resources/assets/Blocks_RGB_160.png</code>
*<code>resources/assets/favicon-16x16.png</code>

Set <code>html_upgrade</code> permissions to 755.  Rename <code>html</code> to <code>html_old</code>, and rename <code>html_upgrade</code> to <code>html</code>.  At this point, requests to the server will likely fail, because the database schema has not been updated.  Change directory to <code>/var/www/html/maintenance</code>, and run the following command:

<code>php update.php</code>

If the schema hasn't been changed, a rollback is as simple as renaming <code>html</code> back to <code>html_upgrade</code>, and <code>html_old</code> back to <code>html</code>.  If the schema has changed, the database will need to be blown up and recreated using the latest backup.  

===Job runner===
There is a bash script at <code>/usr/local/bin/mwjobrunner</code> which runs MediaWiki maintenance scripts every ten seconds.  It is based on this webpage: https://www.mediawiki.org/wiki/Manual:Job_queue#Simple_service_to_run_jobs.  There is no service to run it at startup.

===Cron jobs===
The database is backed up once a day at midnight.  Let's Encrypt renews its certificate every three months.

===Restarting===
If you restart the server, the necessary daemons may not run at startup.  Apache, MySQL, and Parsoid may need to be started manually.

===Mail===
In order for MediaWiki to send mail, [[Peter Stevens]] installed PEAR, Mail, and Net_SMTP.  It is currently configured to send from peterstevens@fas.harvard.edu.  This will be updated with a new address.  The configurations for the SMTP server are located in <code>/var/www/html/LocalSettings.php</code>.  Mail and Net_SMTP are PHP packages located in <code>/usr/share/php/</code>.