Is there a way to make a one way mirror? (Cycles) I'm trying to create a reflection that will repeat an object so it looks like there are infinite but it is only reflecting. Just using white glossy shader doesn't work because it reflects outside.

I'm hoping I can do this with the camera set to orthographic. Probably not though.
You have to use the Geometry node to make difference in the face sides. Here is the guide what I've seen before: Backface culling in cycles

You can set the camera to orthographic in the camera settings in the properties tab.

I made a native file for this: https://blend-exchange.giantcowfilms.com/b/6020/