if __name__ == "__main__" :
    try:
        vir_domain, action = sys.argv[1:3]
    except:
        exit(0)
    log(sys.argv)
    if action == 'release':
        try:
          conn = libvirt.open(None)
          machine = conn.lookupByName(vir_domain)
		  ...
        except:
          pass