Camera choice and mounting

I have an outdoor area covered by a wire mesh cage. There are two doors. I want to cover this area with one camera. I could do it with a camera mounted on one of the aluminum struts that make the frame. There are two challenges. 1) There is no way of running power to the strut, so battery power seems vital. 2) At best the strut is 2 inches wide and I cannot drill into it without damaging the structural integrity.

What would you recommend as the best camera choice, and how would you suggest I mount it?