Leak in the roof

The strong rain finally confirmed it: there is a leak in the roof. The roof is one large piece of milky-transparent PVC, not very thick, quite bendy. It is attached to the metal box by rivets which go through a metal L-bar. Water is probably coming in either at those rivets, or at the gap between that metal and the roof PVC sheet.

There are only droplets getting through. The water seems to migrate along the inside metal, until it finds the lowest point - which is right where my pillow is in the bedroom.

I collected the droplets:

Not much that I can do right now. Seems to be the only place where water gets in.