The suggestion above for the Fenix L2D agrees with my thoughts. I've run through a number of lighting options with commuting including building my own headlight (halogen 20w), side and rear lights (LEDs) with a 12 ah rechargeable. But after buying a Fenix L2D, I can fully recommend that as the way to go (if you carry a small batter charger with you).
With two AA batteries, the Fenix runs for over two hours on turbo mode (175 to 180 lumens), or 4 hours on high (100 lumens), or 10 hours on medium (50 lumens), or lastly, 55 hours on low (11 lumens -- good for in the tent reading or around the camp site walking).
Buy Twofish mounts; 3 here for $15:
https://www.fenix-store.com/product_...roducts_id=274
This mounting option makes installing and removing the flashlight easy and fast. In addition, with the Fenix light you have a light that works as headlight and also as flashlight around camp. I'll be using this combination for my tour this summer.
Of course, if you don't want to carry a small recharger or buy new batteries, then probably a generator type light is the better option.