Revert "Revert back"

This reverts commit 8afa220.

src/fetcher/messaging.py

@@ -32,6 +32,17 @@ def _create_ssl_context(self, ssl_params):
         return context
 
 
+    async def _init_channel(self):
+        """Initialize the channel and set QoS"""
+        self.channel = await self.connection.channel()
+        await self.channel.set_qos(prefetch_count=MAX_MESSAGES)
+
+    async def _ensure_channel(self):
+        """Ensure that the channel is open and ready"""
+        if self.channel is None or self.channel.is_closed:
+            logger.warning("Channel is closed or not initialized. Re-initializing...")
+            await self._init_channel()
+
     async def connect(self, ssl_params=None):
         """Establish a connection to the message broker"""
 
@@ -53,8 +64,7 @@ async def connect(self, ssl_params=None):
                     heartbeat=60,
                     timeout=30
                 )
-                self.channel = await self.connection.channel()
-                await self.channel.set_qos(prefetch_count=MAX_MESSAGES)
+                await self._init_channel()
                 logger.info(f"Connected to the RabbitMQ server at {self.host}")
                 break  # Exit the loop if connection is successful
             except AMQPConnectionError as e:
@@ -68,12 +78,14 @@ async def connect(self, ssl_params=None):
 
     async def setup_queues(self, **queues):
         """Declare necessary queues and thier durability"""
+        await self._ensure_channel()
         for queue_name, durable in queues.items():
             queue = await self.channel.declare_queue(queue_name, durable=durable)
             self.queues[queue_name] = queue
 
     async def publish_message(self, queue_name, message_body, headers=None):
         """Publish a message to the specified queue"""
+        await self._ensure_channel()
         message = aio_pika.Message(body=json.dumps(message_body).encode(), headers=headers)
         try:
             await self.channel.default_exchange.publish(
@@ -87,6 +99,7 @@ async def publish_message(self, queue_name, message_body, headers=None):
 
     async def publish_service_message(self, message_body, queue_name="FetcherMetricsQueue", expiration=30, headers=None):
         """Publish a short-lived service message"""
+        await self._ensure_channel()
         message = aio_pika.Message(body=json.dumps(message_body).encode(), expiration=expiration, headers=headers)
         try:
             await self.channel.default_exchange.publish(