Merge pull request #4874 from RasaHQ/kafka-extras

`kafka-python` as extra dependency

changelog/4751.improvement.rst

@@ -0,0 +1,6 @@
+The ``kafka-python`` dependency has become as an "extra" dependency. To use the
+``KafkaEventConsumer``, ``rasa`` has to be installed with the ``[kafka]`` option, i.e.
+
+.. code-block:: bash
+
+  $ pip install rasa[kafka]

docs/api/event-brokers.rst

@@ -114,9 +114,19 @@ example:
 Kafka Event Broker
 ------------------
 
-It is possible to use `Kafka <https://kafka.apache.org/>`_ as main broker for your events. In this example
-we are going to use the `python-kafka <https://kafka-python.readthedocs.io/en/master/usage.html>`_
-library, a Kafka client written in Python.
+It is possible to use `Kafka <https://kafka.apache.org/>`_ as main broker for your
+events. In this example we are going to use the `python-kafka <https://kafka-python
+.readthedocs.io/en/master/usage.html>`_ library, a Kafka client written in Python.
+
+.. note::
+
+  In order to use the Kafka event broker, ``rasa`` has to be installed with the
+  ``kafka`` option:
+
+  .. code-block:: bash
+
+    $ pip install rasa[kafka]
+
 
 Adding a Kafka Event Broker Using the Endpoint Configuration
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

requirements.txt

@@ -49,7 +49,7 @@ python-engineio==3.9.3
 pydot==1.4.1
 async_generator==1.10
 SQLAlchemy~=1.3.3
-kafka-python==1.4.6
+kafka-python==1.4.7
 sklearn-crfsuite==0.3.6
 psycopg2-binary==2.8.2
 PyJWT==1.7.1

setup.py

@@ -81,7 +81,6 @@
     "pydot~=1.4",
     "async_generator~=1.10",
     "SQLAlchemy~=1.3.0",
-    "kafka-python~=1.4",
     "sklearn-crfsuite~=0.3.6",
     "PyJWT~=1.7",
     # remove when tensorflow@1.15.x or a pre-release patch is released
@@ -95,6 +94,7 @@
     "convert": ["tensorflow_text~=1.15.1", "tensorflow_hub~=0.6.0"],
     "mitie": ["mitie"],
     "sql": ["psycopg2~=2.8.2", "SQLAlchemy~=1.3"],
+    "kafka": ["kafka-python~=1.4"],
 }
 
 setup(