Ensure 'volumes_info' always defaults to empty list.

coriolis/conductor/rpc/server.py

@@ -533,10 +533,15 @@ class ConductorServerEndpoint(object):
         execution.type = constants.EXECUTION_TYPE_REPLICA_EXECUTION
 
         for instance in execution.action.instances:
-            # NOTE: we update all of the param values before triggering an
-            # execution to ensure that the latest parameters are used:
+            # NOTE: we default/convert the volumes info to an empty list
+            # to preserve backwards-compatibility with older versions
+            # of Coriolis dating before the scheduling overhaul (PR##114)
             if instance not in replica.info:
                 replica.info[instance] = {'volumes_info': []}
+            elif replica.info[instance].get('volumes_info') is None:
+                 replica.info[instance]['volumes_info'] = []
+            # NOTE: we update all of the param values before triggering an
+            # execution to ensure that the latest parameters are used:
             replica.info[instance].update({
                 "source_environment": replica.source_environment,
                 "target_environment": replica.destination_environment})
@@ -1666,7 +1671,7 @@ class ConductorServerEndpoint(object):
             # When restoring a snapshot in some import providers (OpenStack),
             # a new volume_id is generated. This needs to be updated in the
             # Replica instance as well.
-            volumes_info = task_info.get("volumes_info")
+            volumes_info = task_info.get("volumes_info", [])
             if volumes_info:
                 self._update_volumes_info_for_migration_parent_replica(
                     ctxt, execution.action_id, task.instance,
@@ -1680,7 +1685,7 @@ class ConductorServerEndpoint(object):
                 # ones.
                 self._update_volumes_info_for_migration_parent_replica(
                     ctxt, execution.action_id, task.instance,
-                    {"volumes_info": None})
+                    {"volumes_info": []})
 
         elif task_type in (
                 constants.TASK_TYPE_FINALIZE_REPLICA_INSTANCE_DEPLOYMENT,

coriolis/tasks/replica_tasks.py

@@ -16,7 +16,7 @@ LOG = logging.getLogger(__name__)
 
 
 def _get_volumes_info(task_info):
-    volumes_info = task_info.get("volumes_info")
+    volumes_info = task_info.get("volumes_info", [])
     if not volumes_info:
         raise exception.InvalidActionTasksExecutionState(
             "No volumes information present")
@@ -48,10 +48,10 @@ def _check_ensure_volumes_info_ordering(export_info, volumes_info):
         ordered_volumes_info.append(matching_volumes[0])
 
     vol_info_cpy = utils.filter_chunking_info_for_task(
-        {"volumes_info": volumes_info}).get("volumes_info")
+        {"volumes_info": volumes_info}).get("volumes_info", [])
 
     ordered_vol_info_cpy = utils.filter_chunking_info_for_task(
-        {"volumes_info": ordered_volumes_info}).get("volumes_info")
+        {"volumes_info": ordered_volumes_info}).get("volumes_info", [])
 
     LOG.debug(
         "volumes_info returned by provider for instance "
@@ -198,7 +198,7 @@ class DeployReplicaDisksTask(base.TaskRunner):
             event_handler)
         connection_info = base.get_connection_info(ctxt, destination)
 
-        volumes_info = task_info.get("volumes_info")
+        volumes_info = task_info.get("volumes_info", [])
         volumes_info = provider.deploy_replica_disks(
             ctxt, connection_info, target_environment, instance, export_info,
             volumes_info)