A decade in, Los Angeles-based seven-piece Flogging Molly hasn't strayed far from the punch-drunk exuberance within its mix of Irish traditionalism and working-class pub punk. Unleashing the kind of rowdy anthems that inspire you to get into a fight with a complete stranger and then celebrate by buying him a pint, these boisterous students of the Pogues and the Clash achieved their highest spot on the Billboard 200 with their 2008 studio album, “Float.” Supporting the release a new live album, “Live at the Greek Theatre,” Flogging Molly is scheduled to play the National on Thursday, April 29, at 7 p.m., $25-$28.