**Sto**Feature summary** (what you would like to be able to do and where):
As a MediaWiki developer,Currently it is not possible to to install MediaWiki with an existing LocalSettings.php file. If you include a LocalSettings.php with your current MediaWiki installation and open MediaWiki the first time with an empty database, you will run into database errors. If you try to run `install.php`, you will run into `A LocalSettings.php file has been detected. To upgrade this installation, please run update.php instead`. Trying `update.php` fails as well.
I want to be able to run `docker compose exec mediawiki php maintenance/run.php install` using the settings from an existing LocalSettings.php file**Use case(s)** (list the steps that you performed to discover that problem, and describe the actual underlying problem which you want to solve. Do not describe only a solution):
so that I don't have to rename my old LocalSettings.php file, type a bunch of parameters into the command line, let it run, delete the new LocalSettings.php file, then rename my old LocalSettings.php fileA containerized/exportable version of MediaWiki that can utilize an existing LocalSettings.php and does not have to go through the install process every time when recreated.
**Notes****Benefits** (why should this be implemented?):
* suggest making this change to maintenance/install.php or maintenance/update.php
* I'm not the first person to run into this inefficiency. I found https://www.mediawiki.org/wiki/Topic:Ut4s8i4nbghrc1slEase of testing and reproducing production MediaWikis.