Back in the day, several manufacturers made handlebar mounted racks/decaleurs for traditional front bags. These "rackaleurs" were not intended to replace a front rack on a touring or rando bike, but rather to allow a simple way to mount your bag on a bike that lacked a front rack, on your racing bike for example. In fact I used one on my racing bike for many years and many thousands of miles. It allowed me to carry my ancient Leica camera and some extra cloths on training rides.
Rackaleurs hold the bag higher than is ideal, but if you carry a light load they work quite well. On bumpy roads, however, I recommend using an old toe clip strap or loop of bungy cord to connect the bag to the head tube (as in the photo) to prevent the bag from bouncing around when going over large bumps.
We bought a NOS case of these a couple of years ago ago and they quickly sold out, so we decided to make reproductions. The new rackaleurs just arrived and are now available in the Velo Orange store and through VO dealers.
Note that Rackaleurs fit on traditional quill stems, those shaped like the Nitto Technomic. They don't work with most threadless stems because threadless stems are usually too wide. They do fit on aero-style quill stems, but may need to be bent down a little in order to sit level.