Many times you will find yourself in a situation where you can not use public repository for your code, e.g. free public hosted git repository at Github, because your code is private. In such case, you simply follow the previous steps, but the build is going to fail, because OpenShift will not be able to download the source code as it will not have the credentials to authenticate itself against the git repository.
You can upload some private key to OpenShift and authorize its public counterpart at the git hosting, and with those in place, OpenShift will be able to access your private git repository. I do not want to go into too many details here, you can read more in the documentation linked earlier.
First, generate an RSA key that is going to be uploaded to OpenShift (be careful not to overwrite your current keys)
Do you know if your OpenShift project is currently on budget? If you deploy more containers right now or if OpenShift dynamically increases capacity, would that put your project in the red? Red Hat ...