Add connection open/close callbacks

CHANGES.rst

@@ -1,6 +1,11 @@
 CHANGES
 -------
 
+552.feature
+^^^^^^^^^^^
+
+Add new callbacks for connection opened/close for consumer and producer 
+
 523.feature
 ^^^^^^^^^^^
 

aiokafka/client.py

@@ -137,6 +137,8 @@ def __init__(self, *, loop, bootstrap_servers='localhost',
         self._md_update_fut = None
         self._md_update_waiter = create_future(loop=self._loop)
         self._get_conn_lock = asyncio.Lock(loop=loop)
+        self._on_connection_closed_callback = None
+        self._on_connection_opened_callback = None
 
     def __repr__(self):
         return '<AIOKafkaClient client_id=%s>' % self._client_id
@@ -371,7 +373,24 @@ def set_topics(self, topics):
         self._topics = set(topics)
         return res
 
+    def set_on_connection_closed_callback(self, on_connection_closed_callback):
+        """Set a callback function to invoke when a connection to Kafka is closed
+        Arguments:
+            on_connection_closed_callback: a callback function to call
+        """
+        self._on_connection_closed_callback = on_connection_closed_callback
+
+    def set_on_connection_opened_callback(self, on_connection_opened_callback):
+        """Set a callback function to invoke when a connection to Kafka is opened
+        Arguments:
+            on_connection_opened_callback: a callback function to call
+        """
+        self._on_connection_opened_callback = on_connection_opened_callback
+
     def _on_connection_closed(self, conn, reason):
+        if self._on_connection_closed_callback:
+            self._on_connection_closed_callback(conn, reason)
+
         """ Callback called when connection is closed
         """
         # Connection failures imply that our metadata is stale, so let's
@@ -441,6 +460,9 @@ async def _get_conn(
                 self.force_metadata_update()
             return None
         else:
+            if self._on_connection_opened_callback:
+                self._on_connection_opened_callback(self._conns[conn_id])
+
             return self._conns[conn_id]
 
     async def ready(self, node_id, *, group=ConnectionGroup.DEFAULT):

aiokafka/consumer/consumer.py

@@ -321,6 +321,21 @@ def __del__(self, _warnings=warnings):
                 context['source_traceback'] = self._source_traceback
             self._loop.call_exception_handler(context)
 
+    def set_on_connection_closed_callback(self, on_connection_closed_callback):
+        """Set a callback function to invoke when a connection to Kafka is closed
+        Arguments:
+            on_connection_closed_callback: a callback function to call
+        """
+        self._client.set_on_connection_closed_callback(on_connection_closed_callback)
+
+    def set_on_connection_opened_callback(self, on_connection_opened_callback):
+        """Set a callback function to invoke when a connection to Kafka is opened
+        Arguments:
+            on_connection_opened_callback: a callback function to call
+        """
+        self._client.set_on_connection_opened_callback(on_connection_opened_callback)
+
+
     async def start(self):
         """ Connect to Kafka cluster. This will:
 

aiokafka/producer/producer.py

@@ -549,6 +549,20 @@ async def send_offsets_to_transaction(self, offsets, group_id):
         fut = self._txn_manager.add_offsets_to_txn(formatted_offsets, group_id)
         await asyncio.shield(fut, loop=self._loop)
 
+    def set_on_connection_closed_callback(self, on_connection_closed_callback):
+        """Set a callback function to invoke when a connection to Kafka is closed
+        Arguments:
+            on_connection_closed_callback: a callback function to call
+        """
+        self.client.set_on_connection_closed_callback(on_connection_closed_callback)
+
+    def set_on_connection_opened_callback(self, on_connection_opened_callback):
+        """Set a callback function to invoke when a connection to Kafka is opened
+        Arguments:
+            on_connection_opened_callback: a callback function to call
+        """
+        self.client.set_on_connection_opened_callback(on_connection_opened_callback)
+
 
 class TransactionContext: