This update consists of the following changes:
    1) Add GroupConsumer to the Go sarama_client and modify the Core
    code to use a groupConsumer instead of a partition consumer. This
    change will ensure that multiple consumers (with different group Ids)
    can consume kafka messages from the same topic.
    2) Remove afkak kafka client and replace it with confluent kakfa,
    a change done in voltha 1.x. Modify the code accordingly.
    3) Add a Group Consumer to the Python kakfa client such that
    several instances of an Adapter can consume the same messages from
    the same topic.
    4) Set the datapath_id for the logical device in the Core.

Change-Id: I5d7ced27c9aeca4f6211baa3dc8cb3db861545e4
diff --git a/python/adapters/ponsim_olt/main.py b/python/adapters/ponsim_olt/main.py
index 09b78fc..86b6be0 100755
--- a/python/adapters/ponsim_olt/main.py
+++ b/python/adapters/ponsim_olt/main.py
@@ -63,8 +63,8 @@
     core_topic=os.environ.get('CORE_TOPIC', 'rwcore'),
     interface=os.environ.get('INTERFACE', get_my_primary_interface()),
     instance_id=os.environ.get('INSTANCE_ID', os.environ.get('HOSTNAME', '1')),
-    kafka_adapter=os.environ.get('KAFKA_ADAPTER', '192.168.0.20:9092'),
-    kafka_cluster=os.environ.get('KAFKA_CLUSTER', '10.100.198.220:9092'),
+    kafka_adapter=os.environ.get('KAFKA_ADAPTER', '172.20.10.3:9092'),
+    kafka_cluster=os.environ.get('KAFKA_CLUSTER', '172.20.10.3:9092'),
     backend=os.environ.get('BACKEND', 'none'),
     retry_interval=os.environ.get('RETRY_INTERVAL', 2),
     heartbeat_topic=os.environ.get('HEARTBEAT_TOPIC', "adapters.heartbeat"),
@@ -380,7 +380,7 @@
                     # TODO: Add KV Store object reference
                     kv_store=self.args.backend,
                     default_topic=self.args.name,
-                    # Needs to assign a real class
+                    group_id_prefix=self.args.instance_id,
                     target_cls=ponsim_request_handler
                 )
             ).start()