This bracket set will allow you to use a 1/2" diameter PVC tube as a wall-mounted support rod. The zip file contains two end brackets and a center support, as well as decorative plugs to fill the screw holes.
A few thoughts on the state of 3D printing at home:
No assembly necessary. Just print and affix.
You'll have to supply your own 1/2" PVC pipe or similar rod. Short lengths of rod won't need the center hanger piece.
You'll need to print three of the included bracket plugs and two hanger plugs if you're planning to elegantly conceal your screws.