Background:

With the upcoming migration of production MediaWiki to PHP 8.3 (T360995), we will need to upgrade parsoidtest1001 to facilitate the Content-Transform-Team's round-trip and one-off testing use cases on 8.3.

While we had initially planned to develop a k8s-based solution first (T386246), an "in-place" upgrade like that from the 8.1 migration is more realistic given the expected timeline, where production traffic-serving workloads begin migrating early in Q2.

From discussion with @cscott, it sounds like a good time to make the switch would before the production migration starts, but after we have we have fairly high confidence in 8.3 in general from ongoing testing in mw-debug. In the future, once there's a k8s-based solution available, we would like to be able to offer multi-version testing, where both PHP versions are available for testing Parsoid for the duration of the production migration (i.e., without a "cut over" date like we have here).

Procedure:

See T380485 for prior art from the PHP 8.1 migration earlier this calendar year. There are two parts to this:

• Switch the host itself to 8.3 (operations/puppet change) -- https://gerrit.wikimedia.org/r/1184119
• Update systemd unit names that include the PHP version in test-related code (mediawiki/services/parsoid change) -- https://gerrit.wikimedia.org/r/1185185

Schedule:

We are tentatively targeting some time between 14:00 and 17:00 UTC on Tuesday, September 16th.