My name is Daniel, I'm from oVirt's [1] CI team.
We use mock to provide isolated environments for our tests/builds.
For that purpose, we maintain a tool we call 'mock_runner' [2] that might fit your needs.
Given a script to run and a set of configurations (which are mostly plain list files) such as repositories you need, packages to install inside mock and etc, will build the mock environment for you and run your script.
For more info, you can refer to [3]

[1] https://ovirt.org/
[2] mock_runner code @gerrit
[3] http://ovirt-infra-docs.readthedocs.io/en/latest/CI/Build_and_test_standards/index.html