Merge branch 'master' into 6473-fetch-events-starting-at

[arvados.git] / sdk / python / arvados / events.py

diff --git a/sdk/python/arvados/events.py b/sdk/python/arvados/events.py
index 268692637afb7a45721322f1617b3aea50788d60..b1872002ebe5cd4b6df40fc102d137a61acbb9d1 100644 (file)
--- a/sdk/python/arvados/events.py
+++ b/sdk/python/arvados/events.py
@@ -14,12 +14,8 @@ 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
+    def __init__(self, url, filters, on_event, last_log_id):
+        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:
@@ -32,9 +28,10 @@ class EventClient(WebSocketClient):
         super(EventClient, self).__init__(url, ssl_options=ssl_options)
         self.filters = filters
         self.on_event = on_event
+        self.last_log_id = last_log_id
 
     def opened(self):
-        self.subscribe(self.filters)
+        self.subscribe(self.filters, self.last_log_id)
 
     def received_message(self, m):
         self.on_event(json.loads(str(m)))
@@ -65,6 +62,7 @@ class PollClient(threading.Thread):
             self.filters = [[]]
         self.on_event = on_event
         self.poll_time = poll_time
+        self.daemon = True
         self.stop = threading.Event()
 
     def run(self):
@@ -112,13 +110,13 @@ class PollClient(threading.Thread):
         del self.filters[self.filters.index(filters)]
 
 
-def _subscribe_websocket(api, filters, on_event):
+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")
     uri_with_token = "{}?api_token={}".format(endpoint, api.api_token)
-    client = EventClient(uri_with_token, filters, on_event)
+    client = EventClient(uri_with_token, filters, on_event, last_log_id)
     ok = False
     try:
         client.connect()
@@ -128,18 +126,25 @@ def _subscribe_websocket(api, filters, on_event):
         if not ok:
             client.close_connection()
 
-def subscribe(api, filters, on_event, poll_fallback=15):
-    '''
-    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.
-    '''
+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)
+        return _subscribe_websocket(api, filters, on_event, last_log_id)
 
     try:
-        return _subscribe_websocket(api, filters, on_event)
+        return _subscribe_websocket(api, filters, on_event, last_log_id)
     except Exception as e:
         _logger.warn("Falling back to polling after websocket error: %s" % e)
     p = PollClient(api, filters, on_event, poll_fallback)