RabbitMQ app_id message property

CHANGELOG.rst

@@ -12,10 +12,13 @@ This project adheres to `Semantic Versioning`_ starting with version 1.0.
 
 Added
 -----
+- ``PikaEventProducer`` adds the RabbitMQ ``App ID`` message property to published
+  messages with the value of the ``RASA_ENVIRONMENT`` environment variable. The
+  message property will not be assigned if this environment variable isn't set.
 
 Changed
 -------
-- updated mattermost connector documentation to be more clear.
+- Updated Mattermost connector documentation to be more clear.
 - Updated format strings to f-strings where appropriate.
 
 Removed

rasa/core/brokers/pika.py

@@ -12,10 +12,11 @@
 from rasa.constants import ENV_LOG_LEVEL_LIBRARIES, DEFAULT_LOG_LEVEL_LIBRARIES
 from rasa.core.brokers.event_channel import EventChannel
 from rasa.utils.endpoints import EndpointConfig
+from rasa.utils.io import DEFAULT_ENCODING
 
 if typing.TYPE_CHECKING:
     from pika.adapters.blocking_connection import BlockingChannel
-    from pika import SelectConnection, BlockingConnection
+    from pika import SelectConnection, BlockingConnection, BasicProperties
     from pika.channel import Channel
     from pika.connection import Parameters, Connection
 
@@ -139,16 +140,16 @@ def initialise_pika_channel(
     """Initialise a Pika channel with a durable queue.
 
     Args:
-        host: Pika host
-        queue: Pika queue to declare
-        username: username for authentication with Pika host
-        password: password for authentication with Pika host
-        port: port of the Pika host
-        connection_attempts: number of channel attempts before giving up
-        retry_delay_in_seconds: delay in seconds between channel attempts
+        host: Pika host.
+        queue: Pika queue to declare.
+        username: Username for authentication with Pika host.
+        password: Password for authentication with Pika host.
+        port: port of the Pika host.
+        connection_attempts: Number of channel attempts before giving up.
+        retry_delay_in_seconds: Delay in seconds between channel attempts.
 
     Returns:
-        Pika `BlockingChannel` with declared queue
+        Pika `BlockingChannel` with declared queue.
 
     """
 
@@ -206,6 +207,17 @@ def __init__(
             ENV_LOG_LEVEL_LIBRARIES, DEFAULT_LOG_LEVEL_LIBRARIES
         ),
     ):
+        """RabbitMQ event producer.
+
+        Args:
+            host: Pika host.
+            username: Username for authentication with Pika host.
+            password: Password for authentication with Pika host.
+            port: port of the Pika host.
+            queue: Pika queue to declare.
+            loglevel: Logging level.
+
+        """
         logging.getLogger("pika").setLevel(loglevel)
 
         self.queue = queue
@@ -224,6 +236,10 @@ def __del__(self) -> None:
             close_pika_channel(self.channel)
             close_pika_connection(self.channel.connection)
 
+    @property
+    def rasa_environment(self) -> Optional[Text]:
+        return os.environ.get("RASA_ENVIRONMENT")
+
     @classmethod
     def from_endpoint_config(
         cls, broker_config: Optional["EndpointConfig"]
@@ -285,7 +301,6 @@ def publish(
         body = json.dumps(event)
 
         while retries:
-            # noinspection PyBroadException
             try:
                 self._publish(body)
                 return
@@ -304,6 +319,22 @@ def publish(
             "'{}':\n{}".format(self.queue, self.host, body)
         )
 
+    @property
+    def _message_properties(self) -> "BasicProperties":
+        """Create RabbitMQ message properties.
+
+        Returns:
+            pika.spec.BasicProperties with the `RASA_ENVIRONMENT` environment
+            variable as the properties' app_id value. If this variable is unset, empty
+            pika.spec.BasicProperties.
+
+        """
+        from pika.spec import BasicProperties
+
+        kwargs = {"app_id": self.rasa_environment} if self.rasa_environment else {}
+
+        return BasicProperties(**kwargs)
+
     def _publish(self, body: Text) -> None:
         if self._pika_connection.is_closed:
             # Try to reset connection
@@ -317,7 +348,12 @@ def _publish(self, body: Text) -> None:
             )
             self._unpublished_messages.append(body)
         else:
-            self.channel.basic_publish("", self.queue, body)
+            self.channel.basic_publish(
+                "",
+                self.queue,
+                body.encode(DEFAULT_ENCODING),
+                properties=self._message_properties,
+            )
 
             logger.debug(
                 f"Published Pika events to queue '{self.queue}' on host "

tests/core/test_broker.py

@@ -1,4 +1,7 @@
 import json
+from unittest.mock import patch
+
+from _pytest.monkeypatch import MonkeyPatch
 
 import rasa.core.brokers.utils as broker_utils
 from rasa.core.brokers.file_producer import FileProducer
@@ -28,6 +31,22 @@ def test_pika_broker_from_config():
     assert actual.queue == "queue"
 
 
+# noinspection PyProtectedMember
+def test_pika_message_property_app_id(monkeypatch: MonkeyPatch):
+    # patch PikaProducer so it doesn't try to connect to RabbitMQ on init
+    with patch.object(PikaProducer, "_run_pika", lambda _: None):
+        pika_producer = PikaProducer("", "", "")
+
+    # unset RASA_ENVIRONMENT env var results in empty App ID
+    monkeypatch.delenv("RASA_ENVIRONMENT", raising=False)
+    assert not pika_producer._message_properties.app_id
+
+    # setting it to some value results in that value as the App ID
+    rasa_environment = "some-test-environment"
+    monkeypatch.setenv("RASA_ENVIRONMENT", rasa_environment)
+    assert pika_producer._message_properties.app_id == rasa_environment
+
+
 def test_no_broker_in_config():
     cfg = read_endpoint_config(DEFAULT_ENDPOINTS_FILE, "event_broker")