Added support for multiple notification topics in NotificationReceiver

In order to receive notificatins for multiple notification topic
types (e.g. both audit-notification and security-notification),
it was necessary to add support for specifying mnore than just
a single topic name when creating a NotificationReceiver object.

Signed-off-by: Andreas Maier <[email protected]>

docs/changes.rst

@@ -78,6 +78,9 @@ Released: not yet
   compatibility. This allows displaying HMC timestamps in local time rather
   than just UTC time.
 
+* Added support for specifying multiple notification topics to
+  `zhmcclient.NotificationReceiver`.
+
 **Known issues:**
 
 * See `list of open issues`_.

tests/unit/zhmcclient/test_notification.py

@@ -44,9 +44,7 @@ def __init__(self, *args, **kwargs):
         self._connect_userid = None
         self._connect_password = None
         self._connect_wait = None
-        self._subscribe_destination = None
-        self._subscribe_id = None
-        self._subscribe_ack = None
+        self._subscriptions = []  # items: tuple(dest, id, ack)
         self._queued_messages = []  # items: tuple(headers, message_str)
         self._sender_thread = None
 
@@ -70,9 +68,7 @@ def connect(self, userid, password, wait):
     def subscribe(self, destination, id, ack):
         """Mocks the same-named method of stomp.Connection."""
         assert self._state_connected
-        self._subscribe_destination = destination
-        self._subscribe_id = id
-        self._subscribe_ack = ack
+        self._subscriptions.append((destination, id, ack))
 
     def disconnect(self):
         """Mocks the same-named method of stomp.Connection."""
@@ -123,7 +119,7 @@ def receive_notifications(receiver):
     return msg_items
 
 
-class TestNotification(object):
+class TestNotification_OneTopic(object):
 
     def setup_method(self):
         self.topic = 'fake-topic'
@@ -166,3 +162,48 @@ def test_one_message(self):
         msg0 = msg_items[0]
         assert msg0[0] == self.std_headers
         assert msg0[1] == message_obj
+
+
+class TestNotification_TwoTopics(object):
+
+    def setup_method(self):
+        self.topics = ('fake-topic1', 'fake-topic2')
+        self.hmc = 'fake-hmc'
+        self.userid = 'fake-userid'
+        self.password = 'fake-password'
+        self.std_headers = {
+            'notification-type': 'fake-type'
+        }
+
+    @patch(target='stomp.Connection', new=MockedStompConnection)
+    def test_no_messages(self):
+        receiver = NotificationReceiver(self.topics, self.hmc, self.userid,
+                                        self.password)
+
+        conn = receiver._conn
+
+        # We do not add any STOMP messages
+
+        conn.mock_start()
+        msg_items = receive_notifications(receiver)
+
+        assert msg_items == []
+
+    @patch(target='stomp.Connection', new=MockedStompConnection)
+    def test_one_message(self):
+        receiver = NotificationReceiver(self.topics, self.hmc, self.userid,
+                                        self.password)
+        conn = receiver._conn
+
+        # Add one STOMP message to be sent
+        message_obj = dict(a=1, b=2)
+        conn.mock_add_message(self.std_headers, message_obj)
+
+        conn.mock_start()
+        msg_items = receive_notifications(receiver)
+
+        assert len(msg_items) == 1
+
+        msg0 = msg_items[0]
+        assert msg0[0] == self.std_headers
+        assert msg0[1] == message_obj

zhmcclient/_notification.py

@@ -76,14 +76,14 @@
 
 class NotificationReceiver(object):
     """
-    A class for receiving HMC notifications that are published to a particular
-    single HMC notification topic.
+    A class for receiving HMC notifications that are published to particular
+    HMC notification topics.
 
     **Experimental:** This class is considered experimental at this point, and
     its API may change incompatibly as long as it is experimental.
 
     Creating an object of this class establishes a JMS session with the
-    HMC and subscribes for a particular HMC notification topic.
+    HMC and subscribes for the specified HMC notification topic(s).
 
     Notification topic strings are created by the HMC in context of a
     particular client session (i.e. :class:`~zhmcclient.Session` object).
@@ -94,11 +94,13 @@ class NotificationReceiver(object):
     originally created.
     """
 
-    def __init__(self, topic, host, userid, password, port=DEFAULT_STOMP_PORT):
+    def __init__(self, topic_names, host, userid, password,
+                 port=DEFAULT_STOMP_PORT):
         """
         Parameters:
 
-          topic (:term:`string`): Name of the HMC notification topic.
+          topic_names (:term:`string` or list/tuple thereof): Name(s) of the
+            HMC notification topic(s).
             Must not be `None`.
 
           host (:term:`string`):
@@ -118,7 +120,9 @@ def __init__(self, topic, host, userid, password, port=DEFAULT_STOMP_PORT):
             STOMP TCP port. Defaults to
             :attr:`~zhmcclient._constants.DEFAULT_STOMP_PORT`.
         """
-        self._topic = topic
+        if not isinstance(topic_names, (list, tuple)):
+            topic_names = [topic_names]
+        self._topic_names = topic_names
         self._host = host
         self._port = port
         self._userid = userid
@@ -149,8 +153,9 @@ def __init__(self, topic, host, userid, password, port=DEFAULT_STOMP_PORT):
         self._conn.start()
         self._conn.connect(self._userid, self._password, wait=True)
 
-        dest = "/topic/" + topic
-        self._conn.subscribe(destination=dest, id=self._sub_id, ack='auto')
+        for topic_name in self._topic_names:
+            dest = "/topic/" + topic_name
+            self._conn.subscribe(destination=dest, id=self._sub_id, ack='auto')
 
     @logged_api_call
     def notifications(self):
@@ -160,10 +165,18 @@ def notifications(self):
 
         Example::
 
-            receiver = zhmcclient.NotificationReceiver(topic, hmc, userid,
-                                                       password)
+            desired_topic_types = ('security-notification',
+                                   'audit-notification')
+            topics = session.get_notification_topics()
+            topic_names = [t['topic-name']
+                           for t in topics
+                           if t['topic-type'] in desired_topic_types]
+
+            receiver = zhmcclient.NotificationReceiver(
+                topic_names, hmc, userid, password)
+
             for headers, message in receiver.notifications():
-                . . .
+                . . . # processing of topic-specific message format
 
         Yields: