Under the Dome, by Stephen King.
From the Wiki:
"The town of Chesters Mill (pop. approximately 2000) is suddenly cut off from the rest of the world by an invisible barrier, preventing anything other than a small amount of air from passing through. What follows is mostly told from the perspective of Dale "Barbie" Barbara, a former Army lieutenant. After "Dome Day" as it comes to be called, the town quickly collapses into anarchy, as a small war breaks out between the power-hungry second selectman James "Big Jim" Rennie, and a portion of the townsfolk. Resources quickly begin to dwindle, and many begin to resort to monstrous acts of violence to survive."
The book was released last month. The Kindle edition will be available in about 3 days.