Mediawiki - Support for multiple seperate wikis

[Ernstian]

Mediawiki is already supported, but there are two problems that I noticed while using it:

1. The smaller problem: the path /wiki/ is hardcoded, and I'm not sure if I can change it without breaking stuff. This is a problem if I want to use "Short URLS" (in short: Currently, it's "https://example.org/wiki/index.php?title=Page_title", it's possible to make it more accessible it being "https://example.org/wiki/Page_title" (like Wikipedia has it), but that needs a different installation path than /wiki/)
2. The main thing: I'm using the wiki for my pen and paper campaign, which works incredibly well (if you run a long-term campaign, try a wiki!). I'm thinking about starting another campaign soon, for which I want to provide another wiki. Installing another wiki does not work with dietpi out of the box.

I'm not sure how feasable it is, but I'd like to choose a "wikiname" or something during installation. The database and the website path should reflect that name and should be fully seperate (so I could uninstall one wiki, but keep the other intact): "https://example.org/wiki1/" and "https://example.org/wiki2/", for example. Something like a wiki family with "Separate settings files" sounds like it would perfectly fit my use case.

[MichaIng]

@Ernstian
Why does the /wiki path breaks the short URLs? Following the guide for e.g. Lighttpd:

url.rewrite-if-not-file = ( 
    "^/wiki/(mw-)?config/?" => "$0",
    "^/wiki/([^?]*)(?:\?(.*))?" => "/w/index.php?title=$1&$2",
    "^/wiki/([^?]*)" => "/w/index.php?title=$1",
    "^/wiki$" => "/w/index.php", # to avoid 404 when the user types /wiki instead of /wiki/
)

So there the base installation is in /w. With it being in /wiki, the following should do:

url.rewrite-if-not-file = ( 
    "^/wiki/(mw-)?config/?" => "$0",
    "^/wiki/([^?]*)(?:\?(.*))?" => "/wiki/index.php?title=$1&$2",
    "^/wiki/([^?]*)" => "/wiki/index.php?title=$1",
    "^/wiki$" => "/wiki/index.php", # to avoid 404 when the user types /wiki instead of /wiki/
)`

Just replacing /w with /wiki. This works because url.rewrite-if-not-file only applies for URLs which do not point to a file (like /wiki/index.php) yet. Actually this way of shorting URLs is the more common one, using the base installation path, just removing the index.php and in case turning arguments into path elements.

We could actually implement these shortings OOTB to your webserver drop-ins. I guess, on Apache, it does work OOTB already via .htaccess.

It would be indeed not so difficult to implement a custom path/wiki name, with an optional dialogue and dietpi.txt entry for automation. But a problem for multiple installations is that dietpi-software knows only installed and no installed. It would still work with a reinstall and choosing another name/path, but e.g. for updating, again the path would need to be changed back. It would work, but somehow feels hacky/not right. Could be made a little better with some auto-detection of existing MediaWiki instances, checking for some /var/www/*/<key_file> that is unique to MediaWiki, then, in case, showing a menu to select the instance which shall be reinstalled/updated.

Btw, does MediaWiki have an internal updater, or do files need to be replaced manually?

[MichaIng]

Regarding /var/www/wiki/wiki1... I think having them correctly named in the document root is better, as then it does not solely rely on rewrite rules, but the instance can be accessed via domain.org/name in any case. That way also we do not need to perform any migration for existing installs, which are not distributed in sub directories, yet + create rewrite rules etc.

There is actually a web updater as well, but it is not recommended, as it is a single script, which can exceed the PHP execution limit: https://www.mediawiki.org/wiki/Manual:Upgrading#Web_updater

Okay, actually something we should add to your docs: reinstall first, then running the database update via CLI.

[Ernstian]

I just noticed why I thought it's a problem if the wiki is located in /wiki: There's a warning on the Short URLs page (which includes a guide to move the wiki)

A common beginner's mistake is to install MediaWiki itself (the source code, not the short URL) in /wiki instead of /w. Once installed they would realize the mistake when trying to configure Short URLs (which would become difficult as the virtual path then conflicts with the real path).

There also is a warning on the lighttpd guide:

Please note the installation path (/w/ above) and the virtual path to access articles (/wiki/ above) must be different, or the styles won't load at all (and other issues, with extensions for instance), as explained in the main article

I guess I'll stay away from this for now - never change a running system :) The bigger problem for me way the multiple wiki system anyway. Thank you for looking into it!

[MichaIng]

This is only because of their particular configs which do the rewrite even if the file exists, and in case of Lighttpd I do not see the issue at all. But I will do some tests.

[Ernstian]

Thank you so much for your work.

I took a look at the installation script for mediawiki in dietpi-software. Am I understanding right that, for creating a new mediawiki installation after having one installed by dietpi, the only steps I need to take are:

1. Create a new database table:
   /boot/dietpi/func/create_mysql_db newwikiname mediawiki masterpassword
2. Curl mediawiki, export it to /var/www/newwikiname and chown to www-data

And then go through the normal setup wizard by mediawiki, using newwikiname with user mediawiki for the database?

And for uninstalling, I can just delete /var/www/newwikiname and drop table newwikiname?

[MichaIng]

Jep exactly that. For uninstall and reinstall, if there is no good safe file to identify MediaWiki, we could also create an own dotfile like .dietpi-mediawiki or something like that, so we do not accidentally remove other dirs.