Root user not created with default docker-compose.yml

I have followed the instructions in the quick start and, after downloading docker-compose.yml and setting the keys, I ran docker-compose up and waited a bit. Connecting to the Gitlab instance presented me with the login screen, but no credentials worked. Connecting to the PGSQL container I tried a SELECT COUNT(*) FROM USERS, which resulted in a count of 0 rows.

I solved the problem by running docker-compose down, setting GITLAB_ROOT_PASSWORD within docker-compose.yml, doing docker-compose up and then manually running the setup by connecting to the gitlab container with docker exec -it gitlab_gitlab_1 /bin/bash (where gitlab_gitlab_1 was the name of my container, got it with docker-compose ps) and running bin/rake gitlab:setup.

Is this expected behavior?

Start with the downloaded default docker-compose.yml and reproduce the quick-start flow using docker-compose up, then check the GitLab container and PostgreSQL users table as described. Compare this with the manual bin/rake gitlab:setup step; done means determining whether the default setup should create a root user and documenting or correcting the expected behavior.