fix: handle duplicate module UUID better; default to schedule on pyruntime

Author: nampereira

handlers/control.py

@@ -15,6 +15,9 @@
 class Control(ControlHandler):
     """Runtime control messages."""
 
+    # if parent is not given will default to schedule on this runtime
+    __DFT_RUNTIME_NAME="pyruntime"
+    
     def __init__(self, *args, **kwargs):
         self.topic = settings.MQTT_CONTROL
         self._log = logging.getLogger("control")
@@ -36,7 +39,12 @@ def __get_runtime_or_schedule(self, msg, module):
         #        rt = msg.get('data', 'parent')
         #        sched_ret = self._get_object(rt, model=Runtime)
         # return sched_ret
-        return self._get_object(msg.get('data', 'parent'), model=Runtime)
+        try:
+            parent_id = msg.get('data', 'parent')
+        except messages.MissingField:
+            return self._get_object(Control.__DFT_RUNTIME_NAME, model=Runtime)
+            
+        return self._get_object(parent_id, model=Runtime)
 
     def create_module(self, msg):
         """Handle create message."""
@@ -46,14 +54,27 @@ def create_module(self, msg):
         if 'filetype' not in data:
             data['filetype'] = FileType.WA
 
-        module = self._object_from_dict(Module, data)
-        module.parent = self.__get_runtime_or_schedule(msg, module)
+        module_id = msg.get('data', 'uuid') 
 
+        module = None
+        try: 
+            module = self._get_object(module_id, model=Module)
+            if module.status == State.ALIVE:
+                # module is running, will error out with a duplicate UUID
+                raise messages.DuplicateUUID(data, obj_type='module')
+            else: 
+                module.status = State.ALIVE
+        except messages.UUIDNotFound:
+            # ok, will create a new one
+            module = self._object_from_dict(Module, data)
+                    
+        module.parent = self.__get_runtime_or_schedule(msg, module)
+        
         try:
             module.save()
         except IntegrityError as e:
             if 'UNIQUE constraint' in str(e):
-                raise messages.DuplicateUUID(data, obj_type='module')
+                raise messages.DuplicateUUID(data, obj_type='module') # should not happen!
 
         return messages.Request(
             "{}/{}".format(msg.topic, module.parent.uuid),

pubsub/messages.py

@@ -99,7 +99,7 @@ class UUIDNotFound(SLException):
 
     def __init__(self, obj, obj_type="runtime"):
         super().__init__(
-            {"desc": "invalid {} UUID".format(obj_type), "data": obj})
+            {"desc": "invalid {} Name/UUID".format(obj_type), "data": obj})
 
 
 class DuplicateUUID(SLException):