For a research project I am comparing PaaS providers. I'm however not sure about the following. On App Engine I can have multiple live versions of my application. If I have a new version and I deploy it I can reach it on a non-default url like: versionX.myapp.appspot.com. I can use that url to test it while running on the PaaS. Once I'm happy with the result I will change the default version and my visitors will also see the changes.
I am wondering if Openshift has something simular? Only thing I found so far is that it deploys on git push and if it fails to build it will leave the old version live. This of course still leaves a risk for functional errors. If I then still have to install a test-server locally I am still doing system administration and it would be nice if this can be prevented.
How is this best resolved when using openshift?
Edit: I did found this article: https://www.openshift.com/blogs/release-management-in-the-cloud
Is that the way to or are there other common ways to do this?
The best way to re-create the google functionality would be to run a dev/qa instance on a separate gear and add those git repositories as remotes to your local git working copy, then you can git push to any environment for testing before you deploy to production.