i know spotlights again

hi I know there are many posts on spotlight's but I know how to wire them up I am just wondering the best way to run the loom from the roof bar to inside the cab as that's where my relays are could I drill a small hole in the roof or is there a better way of doing it?
thank you in advance
bob

Hole in roof, 'proper' waterproof gland is what I used.

Thank you Paul that's what I was thinking just wanted to see what everyone else has done 1st