Have you seen the Eagle gas cans? About as safe as you are going to get for a gas can. Spring loaded pour spout. Funnel is removable.
https://www.amazon.com/Eagle-UI-50-FS-Galvanized-Gasoline-Capacity/dp/B00GVJAXZQ/ref=sr_1_1?ie=UTF8&qid=1469790355&sr=8-1&keywords=eagle+fuel+can
https://www.amazon.com/Eagle-UI-50-FS-Galvanized-Gasoline-Capacity/dp/B00GVJAXZQ/ref=sr_1_1?ie=UTF8&qid=1469790355&sr=8-1&keywords=eagle+fuel+canOne thing to keep in mind if and when you setup a system to get fuel from your trucks tank... don't empty the tank! If you don't pay attention, that generator putting away on the other side of the camper (for noise reduction) will suck the fuel tank dry. And then you are really stuck.