__init__.py

class RollingRestart():
  
  def depool():
  
  def check depool()
  
  def restart()
  
 
supprted_damons = {
  'apache': RollingRestartApache,
  'hhvm': RollingRestartHhvm
}

def run():
  daemons = [supprted_damons[i] for i in args.damons if supprted_damons.get(i,None)]
  # set host icinga down time
  # possibly host depool
  for daemon in daemons:
    damons.depool()
    while damon.check_depool():
      sleep
    daemons.restart()
    damons.repool()
    

apache.py

RollingRestartApache(RollingRestart):
  def check_depool():
    #apache depool