fix list_service method not returning expected response (#787)

comps/cores/mega/gateway.py

@@ -72,8 +72,19 @@
 
     def list_service(self):
         response = {}
-        for node in self.all_leaves():
-            response = {self.services[node].description: self.services[node].endpoint_path}
+        for node, service in self.megaservice.services.items():
+            # Check if the service has a 'description' attribute and it is not None
+            if hasattr(service, "description") and service.description:
+                response[node] = {"description": service.description}
+            # Check if the service has an 'endpoint' attribute and it is not None
+            if hasattr(service, "endpoint") and service.endpoint:
+                if node in response:
+                    response[node]["endpoint"] = service.endpoint
+                else:
+                    response[node] = {"endpoint": service.endpoint}
+            # If neither 'description' nor 'endpoint' is available, add an error message for the node
+            if node not in response:
+                response[node] = {"error": f"Service node {node} does not have 'description' or 'endpoint' attribute."}
         return response
 
     def list_parameter(self):

comps/cores/mega/micro_service.py

@@ -38,6 +38,7 @@ def __init__(
         provider: Optional[str] = None,
         provider_endpoint: Optional[str] = None,
         use_remote_service: Optional[bool] = False,
+        description: Optional[str] = None,
         dynamic_batching: bool = False,
         dynamic_batching_timeout: int = 1,
         dynamic_batching_max_batch_size: int = 32,
@@ -53,6 +54,7 @@ def __init__(
         self.input_datatype = input_datatype
         self.output_datatype = output_datatype
         self.use_remote_service = use_remote_service
+        self.description = description
         self.dynamic_batching = dynamic_batching
         self.dynamic_batching_timeout = dynamic_batching_timeout
         self.dynamic_batching_max_batch_size = dynamic_batching_max_batch_size