Kegging with...barrels?!

Oooooookay boys and girls, I've been wondering this for THE LONGEST time. Ever see a commercial where a guy pulls a nice, carbonated pint straight from the spiggot of a huge wooden barrel, drinking deep the oak aged nectar of kings? Well I've always wanted to know: is that actually possible? Im thinking that, in theory, you could just age your beer in your barrels, add your priming sugar, and (if its airtight) it should yield carbonated, oak aged beer straight from the 'tap', right? Kinda like kegging without the CO2. Granted, it would probably just blow the bung off the top of the barrel, but I have to know. Please respond, and help this grumpy Viking out! Cheers!

Anything is possible on TV.

Barrels definitely aren't airtight. You lose volume when you barrel age due to evaporation through the barrel walls.

it's called "cask conditioning" & it's the way they used to do it, before someone 'invented' CO2 & kegging

plenty of info about it

brewing tv did a home cask conditioning, but they used a metal cask. but there's another episode where they go to a commercial brewery & show dude filling an oak cask.

I know it wouldn't be exactly the same or nearly as cool , but what about barrel aging , and then kegging it ?