I'm not trying to discourage DIY, or even DIY electrical. But, if you choose to build the above DIY, please be careful. As shown, it is a relatively dangerous item.
The plastic fixture is not likely rated for this type of installation. The enclosed bulb will result in a build up of heat, which could easily melt the plastic fixture and compromise the electrical connections. The cord is not grounded and is unprotected as it enters the can through a sharp edged hole in the sheet metal. And finally, the metallic can is not grounded and could become energized if the fixture or cord is compromised. Touching the can while energized could result in death.
ALWAYS use a GFCI protected circuit/outlet for all your brewery tools.