Side roof lights Tapping into dome light

I want to install side lights on my roof rack, but want it tied to my dome light.

Is there a write up somewhere?
As to which and where the wiring harness for that goes to?

IE: when I open the door, the stock dome light turns on. With the side lights that illuminates the outside of the vehicle.

 

The dome light is 12v, tap into it where the switch is on only for the door

 

The door switch(s) is a trigger.
OP, you'll need a gadget that activates with the cab illumination trigger (negative). This will provide a positive trigger for an added relay to the roof rack lamps.