I have a 2002 heavy duty chevy with a duramax diesel, I have a deisel leak

What is your question?

The leak seems to be coming out of a hole in a housing underneath the engine. I have a video of the leak. Leak is not coming from fuel lines. The leak starts when the engine is shut off and starts when the engine is cooling down. I lose 1 to 2 gallons of diesel fuel then it stops. Please help