I don't know how to do this myself. I had a look at https://wikitech.wikimedia.org/wiki/Nova_Resource:Deployment-prep/How_code_is_updated

operations/puppet.git doesn't seem to point to a specific release: just profile::restbase::citoid_uri: http://deployment-docker-citoid02.deployment-prep.eqiad1.wikimedia.cloud:1970

How is this http://deployment-docker-citoid02.deployment-prep.eqiad1.wikimedia.cloud:1970 updated?

These services run in docker managed by systemd on the host:

https://gerrit.wikimedia.org/r/plugins/gitiles/cloud/instance-puppet/+/master/deployment-prep/deployment-docker-citoid02.deployment-prep.eqiad1.wikimedia.cloud.yaml#33

Populates: https://gerrit.wikimedia.org/r/plugins/gitiles/operations/puppet/+/refs/heads/production/modules/service/manifests/docker.pp

update puppet, sudo puppet agent -t on the host, done.

@Mvolz The hints from @thcipriani are leading in the right direction, but probably not super clear. I think the explicit steps needed are:

• Determine the exact tag from https://docker-registry.wikimedia.org/wikimedia/mediawiki-services-citoid/tags/ that you want to deploy
• Use https://horizon.wikimedia.org
  • Select the deployment-prep project
  • Open the Compute → Instances screen
  • Search for the current deployment-docker-citoid instance name using the filters at the top of the Instances screen
  • Click on the instance name (deployment-docker-citoid02 at the moment I am writing this; and likely for quite a while to come)
  • In the instance's screen click on the Puppet Configuration tab
  • Scroll to the bottom of the page and hit Edit to edit the Hiera Config specific to this instance
  • Under the mediawiki-services-citoid entry in profile::docker::runner::service_defs update the version line to match the tag you have selected
  • Click Apply Changes to save the settings
• Ssh to the same instance in deployment-prep (ie ssh deployment-docker-citoid02.deployment-prep.eqiad1.wikimedia.cloud)
• Force a puppet run to apply the changes (ie sudo -i puppet agent -tv)
• Make a SAL log entry saying you did this stuff by writing something like !log deployment-docker-citoid02: updated citoid to version $TAG (T380165) in the #wikimedia-releng IRC channel.
• Profit!

This has lingered for a very long time. It should be possible to do something as part of T401839: Migrate deployment-prep away from Debian Bullseye to Bookworm/Trixie where the docker hosts need to be replaced too.