Configuration problem while trying to debug failing migration from 14.9 to 14.10

Following other issues, I am attempting to debug my issues by doing:

docker-compose run -it --rm gitlab bash -c "sudo -HEu git bundle exec rails runner -e production 'puts Gitlab::BackgroundMigration.remaining' RAILS_ENV=production"

which has led to errors about /home/git/gitlab/log being unwritable`. Following more advice, I ended up with:

docker-compose run -it --rm gitlab bash -c "rm -rf /home/git/gitlab/log && sudo -HEu git bundle exec rails runner -e production 'puts Gitlab::BackgroundMigration.remaining' RAILS_ENV=production"

Which runs the command correctly, but fails with the following error, which makes no sense to me:

/home/git/gitlab/vendor/bundle/ruby/2.7.0/gems/activerecord-6.1.4.7/lib/active_record/connection_adapters/postgresql_adapter.rb:83:in rescue in new_client': connection to server at "localhost" (127.0.0.1), port 5432 failed: Connection refused (ActiveRecord::ConnectionNotEstablished)`

PostgreSQL is running on that port and is accepting connections, although of course it is not running on 127.0.0.1, because it is in its own container, and has correctly set DB_HOST=postgresql in GitLabs env variables. But the command seems to ignore these variables, despite being mentioned as working in various issues in this project, so I am at a loss as how to proceed.

If I am completely off-base: how DO I check migration status while using the setup of this repository ?

Start with the docker-compose command in the issue and the reported ActiveRecord PostgreSQL adapter error. Check how DB_HOST and the database connection environment reach the GitLab container, then verify the migration-status command completes against the PostgreSQL container rather than localhost.