-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):
- ssl_options = None
- if re.match(r'(?i)^(true|1|yes)$',
- config.get('ARVADOS_API_HOST_INSECURE', 'no')):
- ssl_options={'cert_reqs': ssl.CERT_NONE}
+ # 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
+ if config.flag_is_true('ARVADOS_API_HOST_INSECURE'):
+ ssl_options['cert_reqs'] = ssl.CERT_NONE
else:
- ssl_options={'cert_reqs': ssl.CERT_REQUIRED}
+ ssl_options['cert_reqs'] = ssl.CERT_REQUIRED
+
+ # 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.filters = [[]]
self.on_event = on_event
self.poll_time = poll_time
+ self.daemon = True
self.stop = threading.Event()
def run(self):
del self.filters[self.filters.index(filters)]
+def _subscribe_websocket(api, filters, on_event):
+ endpoint = api._rootDesc.get('websocketUrl', None)
+ if not endpoint:
+ raise errors.FeatureNotEnabledError(
+ "Server does not advertise a websocket endpoint")
+ uri_with_token = "{}?api_token={}".format(endpoint, api.api_token)
+ client = EventClient(uri_with_token, filters, on_event)
+ ok = False
+ try:
+ client.connect()
+ ok = True
+ return client
+ finally:
+ if not ok:
+ client.close_connection()
+
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:
- 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.start()
- return p
- else:
- _logger.error("Websockets not available")
- return 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.
+ """
+
+ if not poll_fallback:
+ return _subscribe_websocket(api, filters, on_event)
+
+ try:
+ return _subscribe_websocket(api, filters, on_event)
+ except Exception as e:
+ _logger.warn("Falling back to polling after websocket error: %s" % e)
+ p = PollClient(api, filters, on_event, poll_fallback)
+ p.start()
+ return p
projects / arvados.git / blobdiff