During the RelEng SSD pipeline meeting today, we talked about interim solutions to the problem of building a MediaWiki + extensions container from which a service might be exercised by a broad set of tests. The long-term solutions mentioned in T193824 include an ongoing RfC and experimentation with composer. While we are participating in the ongoing RfC process, the logic for extension dependencies already exists within the `integration/config` repo so we could use that logic as part of post-merge to build an image.
What's still needed:
[ ] Container base image - we'll likely need a base image with some version of PHP and a webserver(?) there are (were) images used for CI for PHP
[ ] Jenkins Job that utilizes the requirements logic inside `integration/config` to build a directory that will power functional MediaWiki install with the Math extension
[ ] A Dockerfile or a blubber config that can take that directory and produce a tagged image