At https://gerrit.wikimedia.org/r/#/c/220635/, @Krenair wrote:
I've heard that we don't actually have a way to test OSM changes in the openstack project anymore.
Apparently for MediaWiki testing, MediaWiki-Vagrant is the proven way to go, so this means that role::wikitech needs to be updated to set up a local dummy LDAP server.
Then this role could be applied via Labs-Vagrant on test instances in Labs.