Dockerized Gitlab Container Backup

I am using a GitLab docker image for integration testing of a service I'm helping to develop. Ideally, the image would be a preconfigured snapshot of GitLab with different users and repos available to run tests against. So the problem ends up being, what is a good way to automate the creation of 'snapshots' of GitLab (that can then be versioned etc.)?

My current solution to this problem is to use GitLab's built in backup utility via gitlab-rake gitlab:backup:create after getting GitLab to a state that I want. This then lets me use GitLab's gitlab-rake gitlab:backup:restore in a hook when the container is starting up to get the container back to the state that I expect (the backup having been ADDed in the Dockerfile for the image). This has the advantage of being relatively lightweight (backups are on the order of MBs) and the backups can be checked in to version control.

I have tried using docker export along with docker import to save the state of the container and then create an image based on that state. This has the advantage of being easy to automate since it is directly supported by Docker, but ends up being fairly expensive considering what the goal is (having users and repos available to test against). It also would require the images to be pushed to a registry of some kind in order to be easily distributed. Perhaps this is the best solution because it is well supported though.

I suppose my question is, what is the Docker way of approaching a problem like this?