Service Container for integration tests

Hi, got a question about drone 0.4
My scenario:
I’m running tests on my app and want to run some integration tests
I’m trying to use compose to rebuild another instance of my own container so that I’m able to ping it’s endpoints.
The question being, where to find some documentation regarding the syntax ?
Tried but not very detailed

Few questions: can I build my image from a Dockerfile or docker-compose.yml ?