Pole barn exterior lights

[3rdgendslmech]

I'm getting ready to wire up a couple lights for the outside of my barn and I was wondering how you guys ran the wire from inside to outside.
I bought 2 motion lights for my personnel door and a weatherproof wall mount. The mount has 5 holes, one in the back and 1 on each side.
I started thinking I'd just drill a hole through the metal and attach the mount to a purlin above the door and use the back hole, but then you don't really have a way to secure the wire to the box other than a nail in clamp on the inside.
If you do it the other way, you mount the box, use a hole on the side and drill a hole through the steel above or below the purlin. Then to be safe to keep from chafing, id put a grommet in or metal clad cable?
What did some of you guys do?

 

[Rickochet]

Are you going through metal on the inside and outside? Do you have the wiring inside the building in conduit or Romex? Post a few pictures of what you are working on and we should be able to help.

 

[Farmallboy15]

I did what you are talking about. Hole through the rear with the light screwed to a girt. I ran a piece of iron pipe/rigid conduit from the back of the light to a workbox on the inside of the barn. I have EMT conduit to all boxes on the inside.