-from ws4py.client.threadedclient import WebSocketClient
-import threading
+import arvados
+import config
+import errors
+
+import logging
import json
-import os
+import threading
import time
-import ssl
+import os
import re
-import config
-import logging
-import arvados
+import ssl
+from ws4py.client.threadedclient import WebSocketClient
_logger = logging.getLogger('arvados.events')
-class EventClient(WebSocketClient):
- def __init__(self, url, filters, on_event):
- # Prefer system's CA certificates (if available)
- ssl_options = {}
- certs_path = '/etc/ssl/certs/ca-certificates.crt'
- if os.path.exists(certs_path):
- ssl_options['ca_certs'] = certs_path
+
+class _EventClient(WebSocketClient):
+ def __init__(self, url, filters, on_event, last_log_id, on_closed):
+ ssl_options = {'ca_certs': arvados.util.ca_certs_path()}
if config.flag_is_true('ARVADOS_API_HOST_INSECURE'):
ssl_options['cert_reqs'] = ssl.CERT_NONE
else:
ssl_options['cert_reqs'] = ssl.CERT_REQUIRED
- super(EventClient, self).__init__(url, ssl_options=ssl_options)
+
+ # Warning: If the host part of url resolves to both IPv6 and
+ # IPv4 addresses (common with "localhost"), only one of them
+ # will be attempted -- and it might not be the right one. See
+ # ws4py's WebSocketBaseClient.__init__.
+ super(_EventClient, self).__init__(url, ssl_options=ssl_options)
+
self.filters = filters
self.on_event = on_event
+ self.last_log_id = last_log_id
+ self._closing_lock = threading.RLock()
+ self._closing = False
+ self._closed = threading.Event()
+ self.on_closed = on_closed
def opened(self):
- self.subscribe(self.filters)
+ for f in self.filters:
+ self.subscribe(f, self.last_log_id)
- def received_message(self, m):
- self.on_event(json.loads(str(m)))
+ def closed(self, code, reason=None):
+ self._closed.set()
+ self.on_closed()
- def close_connection(self):
- try:
- self.sock.shutdown(socket.SHUT_RDWR)
- self.sock.close()
- except:
- pass
-
- def subscribe(self, filters, last_log_id=None):
- m = {"method": "subscribe", "filters": filters}
+ def received_message(self, m):
+ with self._closing_lock:
+ if not self._closing:
+ self.on_event(json.loads(str(m)))
+
+ def close(self, code=1000, reason='', timeout=0):
+ """Close event client and optionally wait for it to finish.
+
+ :timeout: is the number of seconds to wait for ws4py to
+ indicate that the connection has closed.
+ """
+ super(_EventClient, self).close(code, reason)
+ with self._closing_lock:
+ # make sure we don't process any more messages.
+ self._closing = True
+ # wait for ws4py to tell us the connection is closed.
+ self._closed.wait(timeout=timeout)
+
+ def subscribe(self, f, last_log_id=None):
+ m = {"method": "subscribe", "filters": f}
if last_log_id is not None:
m["last_log_id"] = last_log_id
self.send(json.dumps(m))
- def unsubscribe(self, filters):
- self.send(json.dumps({"method": "unsubscribe", "filters": filters}))
+ def unsubscribe(self, f):
+ self.send(json.dumps({"method": "unsubscribe", "filters": f}))
+
+
+class EventClient(object):
+ def __init__(self, url, filters, on_event_cb, last_log_id):
+ self.url = url
+ if filters:
+ self.filters = [filters]
+ else:
+ self.filters = [[]]
+ self.on_event_cb = on_event_cb
+ self.last_log_id = last_log_id
+ self.is_closed = False
+ self.ec = _EventClient(url, self.filters, self.on_event, last_log_id, self.on_closed)
+
+ def connect(self):
+ self.ec.connect()
+
+ def close_connection(self):
+ self.ec.close_connection()
+
+ def subscribe(self, f, last_log_id=None):
+ self.filters.append(f)
+ self.ec.subscribe(f, last_log_id)
+
+ def unsubscribe(self, f):
+ del self.filters[self.filters.index(f)]
+ self.ec.unsubscribe(f)
+
+ def close(self, code=1000, reason='', timeout=0):
+ self.is_closed = True
+ self.ec.close(code, reason, timeout)
+
+ def on_event(self, m):
+ if m.get('id') != None:
+ self.last_log_id = m.get('id')
+ self.on_event_cb(m)
+
+ def on_closed(self):
+ if self.is_closed == False:
+ _logger.warn("Unexpected close. Reconnecting.")
+ self.ec = _EventClient(self.url, self.filters, self.on_event, self.last_log_id, self.on_closed)
+ while True:
+ try:
+ self.ec.connect()
+ break
+ except Exception as e:
+ _logger.warn("Error '%s' during websocket reconnect. Will retry after 5s.", e, exc_info=e)
+ time.sleep(5)
+
class PollClient(threading.Thread):
- def __init__(self, api, filters, on_event, poll_time):
+ def __init__(self, api, filters, on_event, poll_time, last_log_id):
super(PollClient, self).__init__()
self.api = api
if filters:
self.filters = [[]]
self.on_event = on_event
self.poll_time = poll_time
- self.stop = threading.Event()
+ self.daemon = True
+ self.last_log_id = last_log_id
+ self._closing = threading.Event()
+ self._closing_lock = threading.RLock()
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']
+ if self.last_log_id != None:
+ self.id = self.last_log_id
+ else:
+ 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():
+ while not self._closing.is_set():
max_id = self.id
+ moreitems = False
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:
+ items = self.api.logs().list(order="id asc", filters=f+[["id", ">", str(self.id)]]).execute()
+ for i in items["items"]:
if i['id'] > max_id:
max_id = i['id']
- self.on_event(i)
+ with self._closing_lock:
+ if self._closing.is_set():
+ return
+ self.on_event(i)
+ if items["items_available"] > len(items["items"]):
+ moreitems = True
self.id = max_id
- self.stop.wait(self.poll_time)
+ if not moreitems:
+ self._closing.wait(self.poll_time)
def run_forever(self):
# Have to poll here, otherwise KeyboardInterrupt will never get processed.
- while not self.stop.is_set():
- self.stop.wait(1)
+ while not self._closing.is_set():
+ self._closing.wait(1)
- def close(self):
- self.stop.set()
+ def close(self, code=None, reason=None, timeout=0):
+ """Close poll client and optionally wait for it to finish.
+
+ If an :on_event: handler is running in a different thread,
+ first wait (indefinitely) for it to return.
+
+ After closing, wait up to :timeout: seconds for the thread to
+ finish the poll request in progress (if any).
+
+ :code: and :reason: are ignored. They are present for
+ interface compatibility with EventClient.
+ """
+
+ with self._closing_lock:
+ self._closing.set()
try:
- self.join()
+ self.join(timeout=timeout)
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
# to do so raises the same exception."
pass
- def subscribe(self, filters):
+ def subscribe(self, f):
self.on_event({'status': 200})
- self.filters.append(filters)
+ self.filters.append(f)
- def unsubscribe(self, filters):
- del self.filters[self.filters.index(filters)]
+ def unsubscribe(self, f):
+ del self.filters[self.filters.index(f)]
-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
- if 'websocketUrl' in api._rootDesc:
+def _subscribe_websocket(api, filters, on_event, last_log_id=None):
+ endpoint = api._rootDesc.get('websocketUrl', None)
+ if not endpoint:
+ raise errors.FeatureNotEnabledError(
+ "Server does not advertise a websocket endpoint")
+ try:
+ uri_with_token = "{}?api_token={}".format(endpoint, api.api_token)
+ client = EventClient(uri_with_token, filters, on_event, last_log_id)
+ ok = False
try:
- url = "{}?api_token={}".format(api._rootDesc['websocketUrl'], api.api_token)
- ws = EventClient(url, filters, on_event)
- ws.connect()
- 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.daemon = True
- p.start()
- return p
- else:
- _logger.error("Websockets not available")
- return None
+ client.connect()
+ ok = True
+ return client
+ finally:
+ if not ok:
+ client.close_connection()
+ except:
+ _logger.warn("Failed to connect to websockets on %s" % endpoint)
+ raise
+
+
+def subscribe(api, filters, on_event, poll_fallback=15, last_log_id=None):
+ """
+ :api:
+ a client object retrieved from arvados.api(). The caller should not use this client object for anything else after calling subscribe().
+ :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.
+ :last_log_id:
+ Log rows that are newer than the log id
+ """
+
+ if not poll_fallback:
+ return _subscribe_websocket(api, filters, on_event, last_log_id)
+
+ try:
+ if not config.flag_is_true('ARVADOS_DISABLE_WEBSOCKETS'):
+ return _subscribe_websocket(api, filters, on_event, last_log_id)
+ else:
+ _logger.info("Using polling because ARVADOS_DISABLE_WEBSOCKETS is true")
+ except Exception as e:
+ _logger.warn("Falling back to polling after websocket error: %s" % e)
+ p = PollClient(api, filters, on_event, poll_fallback, last_log_id)
+ p.start()
+ return p
projects / arvados.git / blobdiff