This git repository is for mantisbt sites packaged and organized for direct use with openshift. This means that among other things the web application paths will match up to how openshift expects them. You should be able to create a local git repository for yourself that uses both this and your actual openshift application repository as remote sources, and then migrate future updates posted into this repository simply by merging from this remote source and then pushing back to your openshift application repo. The backend database is MySql and the database name is the same as your application name (using $_ENV['OPENSHIFT_APP_NAME']). You can name your application whatever you want. However, the name of the database will always match the application so you might have to update .openshift/action_hooks/build.
Create an account at http://openshift.redhat.com/
Create a php-5.3 application (you can call your application whatever you want)
rhc app create -a bugs -t php-5.4
Add the mysql and phpmyadmin
rhc app cartridge add -a bugs -c mysql-5.1
rhc app cartridge add -a bugs -c phpmyadmin-5.4
Add this upstream bugs repo:
cd bugs
# you may need to remove index.php
git rm php/index.php
git commit -a
git remote add upstream -m master git://github.com/dyfet/openshift-mantisbt.git
git pull -s recursive -X theirs upstream master
# note that the git pull above can be used later to pull updates to
# Etherpad the rm and ln is there until I can figure out github and
# symbolic links
Then push the repo upstream
git push
You can now login to your mantisbt instance and go through it's initial setup. Thats it, your mantisbt is then up and running!