howto/gitlab.md

@@ -1611,6 +1611,16 @@ file, so they need to be manually approved.
 That is done in `tor-puppet.git`, in the `hiera/roles/gitlab.yaml`
 file, the `profile::gitlab::app::major_version` variable.
 
+After upgrades, you might need to update the GitLab Registry metadata
+database with:
+
+```
+# gitlab-ctl registry-database migrate up
+```
+
+Otherwise `containers.torproject.org` will return a 502 error status
+code.
+
 ## SLA
 
 <!-- this describes an acceptable level of service for this service -->