udpated AmqpListener for logging more info on errors

event_bus_utils.py

@@ -2,6 +2,7 @@ import os
 import pika
 import logging
 import threading
+import traceback
 
 # for using it as library and as a __main__
 try:
@@ -18,12 +19,19 @@ class AmqpSynchCallTimeoutError(Exception):
 
 
 class AmqpListener(threading.Thread):
-    COMPONENT_ID = 'amqp_listener_%s' % uuid.uuid1()
+
     DEFAULT_TOPIC_SUSBCRIPTIONS = ['#']
     DEFAULT_EXCHAGE = 'amq.topic'
+    DEFAULT_AMQP_URL = 'amqp://guest:guest@locahost/'
 
     def __init__(self, amqp_url, amqp_exchange, callback, topics=None):
 
+        self.COMPONENT_ID = 'amqp_listener_%s' % str(uuid.uuid4())[:8]
+
+        self.connection = None
+        self.channel = None
+        self.services_queue_name = 'services_queue@%s' % self.COMPONENT_ID
+
         threading.Thread.__init__(self)
 
         if callback is None:
@@ -31,30 +39,36 @@ class AmqpListener(threading.Thread):
         else:
             self.message_dispatcher = callback
 
-        self.connection = pika.BlockingConnection(pika.URLParameters(amqp_url))
-        self.channel = self.connection.channel()
+        if topics:  # subscribe only to passed list
+            self.topics = topics
+        else:
+            self.topics = self.DEFAULT_TOPIC_SUSBCRIPTIONS
 
         if amqp_exchange:
             self.exchange = amqp_exchange
         else:
             self.exchange = self.DEFAULT_EXCHAGE
 
+        if amqp_url:
+            self.amqp_url = amqp_url
+        else:
+            self.amqp_url = self.DEFAULT_AMQP_URL
+
+        self.amqp_connect()
+
+    def amqp_connect(self):
+        self.connection = pika.BlockingConnection(pika.URLParameters(self.amqp_url))
+        self.channel = self.connection.channel()
+
         # queues & default exchange declaration
-        self.services_queue_name = 'services_queue@%s' % self.COMPONENT_ID
         self.channel.queue_declare(queue=self.services_queue_name,
                                    auto_delete=True,
                                    arguments={'x-max-length': 200})
 
-        if topics:  # subscribe only to passed list
-            self.topics = topics
-        else:
-            self.topics = self.DEFAULT_EXCHAGE
-
         for t in self.topics:
             self.channel.queue_bind(exchange=self.exchange,
                                     queue=self.services_queue_name,
                                     routing_key=t)
-
         # Hello world message
         m = MsgTestingToolComponentReady(
             component=self.COMPONENT_ID,
@@ -92,11 +106,13 @@ class AmqpListener(threading.Thread):
             'app_id': props.app_id,
         }
 
-        m = None
         try:
             m = Message.from_json(body)
+            if m is None:
+                raise Exception("Couldnt build message from json %s, amqp props: %s " % (body, props_dict))
             m.update_properties(**props_dict)
             m.routing_key = method.routing_key
+            logging.debug('Message in bus: %s'%repr(m))
             self.message_dispatcher(m)
 
         except NonCompliantMessageFormatError as e:
@@ -104,19 +120,26 @@ class AmqpListener(threading.Thread):
 
         except Exception as e:
             logging.error(e)
-            logging.error('message received:\n\tr_key: %s\n\t%s'%(method.routing_key,body))
+            logging.error('message received:\n\tr_key: %s\n\t%s' % (method.routing_key, body))
+            raise e
 
         finally:
             ch.basic_ack(delivery_tag=method.delivery_tag)
 
     def run(self):
         logging.info("Starting thread listening on the event bus on topics %s" % self.topics)
+
         for i in range(1, 4):
             try:
                 self.channel.start_consuming()
-            except pika.exceptions.ConnectionClosed as err:
-                logging.error('Unexpected connection closed, retrying %s/%s' % (i, 4))
-                logging.error(err)
+
+            except (pika.exceptions.ConnectionClosed,
+                    pika.exceptions.ChannelError,
+                    pika.exceptions.ChannelClosed) as err:
+
+                logging.error('[AmqpListener] Unexpected connection closed, reconnecting %s/%s' % (i, 4))
+                logging.error(traceback.format_exc())
+                self.amqp_connect()
 
         logging.info('Bye byes!')