How can I ground a fluorescent light that I'm attaching a wall outlet plug/cord to?
I'm not sure of the code implications, since that will depend on where you live. But if you're going to put a power cord on a fixture designed to be hardwired with ground, just use a power cord that provides ground as shown. Also, be sure to use a clamp, rather than let the power cord get abraded by the sheet steel fixture of the housing.


This image is from a sink disposal "power cord kit" sold on amazon (US).