All data are lost when the container is stopped.
The default user is admin, password admin.
The image is built locally, there is no dependency to the Docker registry. All data are lost when the container is stopped.
The data is preserved in /srv/mediagoblin.
After installing Dokku, follow the Deploying to Dokku instructions to create the MediaGoblin v0.8.1 app. The following example is based on Dokku installed at gmg.the.re and creates http://loic.gmg.the.re/.
dokku docker-options:add loic deploy "-v /srv/loic:/var/lib/mediagoblin"
To upgrade, remove the app and create a new one after pulling the desired MediaGoblin version.
If the data is preserved in /srv/mediagoblin as described above, upgrade by stopping the container and rebulding the image with the latest stable version.
The git repository has one branch per stable version. The master branch is always the latest stable, not the MediaGoblin development branch. This is to make it so PaaS like Dokku get the latest stable by default instead of the unstable development version.
docker build -t dachary/mediagoblin:$version .
docker build -t dachary/mediagoblin .