def _remove_collector(self,cid):
c = self._get_collector(cid)
c.terminate()
while c.is_alive():
sleep(.2)
output('collector stopped for container %s' % cid)
self.children = [ c for c in self.children if c.name != cid ]
def __init__(self,docker_host,redis_host='127.0.0.1',redis_port=6379):
self.docker = Client(base_url=docker_host)
self.source = self.docker.info()['Name']
self.ncpu = self.docker.info()['NCPU']
self.redis = StrictRedis(host=redis_host,port=redis_port,db=0)
self.children = []
self.stopped = False
log.info('Connected to Docker API at url %s' % docker_host)
output('starting collector on source %s' % self.source)
self.start()
def run_forever(self):
stat_count = 0
output('listener started')
for msg in self.sub.listen():
self._process_msg(msg['data'])
stat_count += 1
if self._is_maint_interval():
output('processed %s stats in last %ss' % \
(stat_count,self.maint_interval))
stat_count = 0
self._flush_all()
def _event_listener(self):
"""
Listen for docker events and dynamically add or remove
stat collectors based on start and die events
"""
output('started event listener')
for event in self.docker.events():
event = json.loads(event.decode('utf-8'))
if event['status'] == 'start':
self._add_collector(event['id'])
if event['status'] == 'die':
self._remove_collector(event['id'])
def _collector(self,cid,cname):
"""
Collector instance collects stats via Docker API streaming web socket,
appending container name and source, and publishing to redis
params:
- cid(str): ID of container to collect stats from
- cname(str): Name of container
"""
sleep(5) # sleep to allow container to fully start
output('started collector for container %s' % cid)
stats = self.docker.stats(cid, decode=True)
for stat in stats:
#append additional information to the returned stat
stat['container_name'] = cname
stat['container_id'] = cid
stat['source'] = self.source
stat['ncpu'] = self.ncpu
self.redis.publish('statsquid', msgpack.packb(stat))
if self.stopped:
break
