Background

Community Configuration has a concept of configuration stores, which are different ways how configuration can be accessed and/or written. As of writing, Community Configuration only has one store implementation: the wiki page store, which stores configuration within a defined wiki-page.

AbuseFilter has a feature called blocked external domains, which allows administrators to block external domains from being linked on the wikis. This feature is currently implemented without CommunityConfiguration, but a migration is on the way in T393240: Special:BlockedExternalDomains should make use of Community Configuration. In the parent task (T401524), the global blacklist (https://meta.wikimedia.org/wiki/Spam_blacklist) should be converted to also use blocked external domains.

Problem

Conceptually, global blocked external domains is a feature that falls within Community Configuration's remit as well. Ordinarily (without CC), it would be implemented by making an internal API request to a central wiki, which would hold the list, and feed it to all the client wikis.

However, it currently cannot be implemented via CC, because Community Configuration cannot access configuration via HTTP. Within this task, we should implement that as another store.

Notes

There is a PoC patch available at https://gerrit.wikimedia.org/r/c/mediawiki/extensions/CommunityConfiguration/+/1031010, which was previously considered for T359185.