send shutdown on sigterm

hbc

@@ -37,6 +37,9 @@ def log(msg):
 	else:
 		print msg
 
+def handler(signum, frame):
+	if signum == signal.SIGTERM:
+		cleanup()		
 
 class NullDevice:
 	def write(self, s):
@@ -329,6 +332,8 @@ def process():
 
 def cleanup():
 	global running
+	if not running:
+		return
 	if verbose: log('cleanup')
 	running = False
 	for conn in conns:
@@ -538,6 +543,7 @@ if fdaemon:
 	daemonized = True
 	syslog.syslog(syslog.LOG_ERR, 'starting heartbeat to %s' % ','.join(hb_hosts))
 
+signal.signal(signal.SIGTERM, handler)
 running = True
 try:
 	process()