import re
import config
import logging
+import arvados
_logger = logging.getLogger('arvados.events')
ssl_options={'cert_reqs': ssl.CERT_NONE}
else:
ssl_options={'cert_reqs': ssl.CERT_REQUIRED}
-
- super(EventClient, self).__init__(url, ssl_options)
- self.filters = []
+ super(EventClient, self).__init__(url, ssl_options=ssl_options)
+ self.filters = filters
self.on_event = on_event
def opened(self):
self.send(json.dumps({"method": "unsubscribe", "filters": filters}))
class PollClient(threading.Thread):
- def __init__(self, api, filters, on_event):
+ def __init__(self, api, filters, on_event, poll_time):
+ super(PollClient, self).__init__()
self.api = api
- self.filters = filters
- self.on_event = on_event
- items = self.api.logs().list(limit=1, order=json.dumps(["id desc"]), filters=json.dumps(filters)).execute()['items']
- if len(items) > 0:
- self.id = items[0]["id"]
+ if filters:
+ self.filters = [filters]
else:
- self.id = 0
- self.loop = True
+ self.filters = [[]]
+ self.on_event = on_event
+ self.poll_time = poll_time
+ self.stop = threading.Event()
+
+ def run(self):
+ self.id = 0
+ for f in self.filters:
+ items = self.api.logs().list(limit=1, order="id desc", filters=f).execute()['items']
+ if items:
+ if items[0]['id'] > self.id:
+ self.id = items[0]['id']
+
+ self.on_event({'status': 200})
+
+ while not self.stop.isSet():
+ max_id = self.id
+ for f in self.filters:
+ items = self.api.logs().list(order="id asc", filters=f+[["id", ">", str(self.id)]]).execute()['items']
+ for i in items:
+ if i['id'] > max_id:
+ max_id = i['id']
+ self.on_event(i)
+ self.id = max_id
+ self.stop.wait(self.poll_time)
def run_forever(self):
- while self.loop:
- time.sleep(15)
- items = self.api.logs().list(limit=1, order=json.dumps(["id asc"]), filters=json.dumps(self.filters+[["id", ">", str(self.id)]])).execute()['items']
- for i in items:
- self.id = i['id']
- self.on_event(i)
+ self.stop.wait()
- def close_connection(self):
- self.loop = False
+ def close(self):
+ self.stop.set()
+ try:
+ self.join()
+ except RuntimeError:
+ # "join() raises a RuntimeError if an attempt is made to join the
+ # current thread as that would cause a deadlock. It is also an
+ # error to join() a thread before it has been started and attempts
+ # to do so raises the same exception."
+ pass
def subscribe(self, filters):
- self.filters += filters
+ self.on_event({'status': 200})
+ self.filters.append(filters)
def unsubscribe(self, filters):
del self.filters[self.filters.index(filters)]
-def subscribe(api, filters, on_event):
+
+def subscribe(api, filters, on_event, poll_fallback=15):
+ '''
+ api: Must be a newly created from arvados.api(cache=False), not shared with the caller, as it may be used by a background thread.
+ filters: Initial subscription filters.
+ on_event: The callback when a message is received
+ poll_fallback: If websockets are not available, fall back to polling every N seconds. If poll_fallback=False, this will return None if websockets are not available.
+ '''
ws = None
- try:
- if 'websocketUrl' in api._rootDesc:
- url = "{}?api_token={}".format(api._rootDesc['websocketUrl'], config.get('ARVADOS_API_TOKEN'))
+ if 'websocketUrl' in api._rootDesc:
+ try:
+ url = "{}?api_token={}".format(api._rootDesc['websocketUrl'], api.api_token)
ws = EventClient(url, filters, on_event)
ws.connect()
- else:
- _logger.info("Web sockets not available, falling back to log table polling")
- ws = PollClient(api, filters, on_event)
- return ws
- except Exception:
- if (ws):
- ws.close_connection()
- try:
- return PollClient(api, filters, on_event)
- except:
- raise
+ return ws
+ except Exception as e:
+ _logger.warn("Got exception %s trying to connect to websockets at %s" % (e, api._rootDesc['websocketUrl']))
+ if ws:
+ ws.close_connection()
+ if poll_fallback:
+ _logger.warn("Websockets not available, falling back to log table polling")
+ p = PollClient(api, filters, on_event, poll_fallback)
+ p.start()
+ return p
+ else:
+ _logger.error("Websockets not available")
+ return None
projects / arvados.git / blobdiff