Error during VNF create returns internal error

* When a user runs vnf-create with an invalid template, the
        client returns am Internal Server Error message instead of
        something useful.  Also the failed VNF device is left in
        the database and must be manually deleted using vnf-delete

      * This patchset catches the heatclient.HTTPException and
        translates it into an HeatClientException subclass of
        TackerException which is able to be passed back to the
        client.  It also deletes the failed VNF entry from the
        database so it does not need to be manually cleaned up.

      * Added device_dict parameter to _create_device_post() call
        when create_device() receives instance_id "None" from a
        failed call to _create_device().  This is an error
        leg that is not normally executed since there should have
        been an exception from the failed device create call.

Closes-Bug: 1468565
Change-Id: Ia2ee8590b7c3bb932328fa0def434ff43e6e52e8

tacker/common/exceptions.py

@@ -319,3 +319,7 @@ class DeviceIDNotOwnedByTenant(Conflict):
 
 class InvalidCIDR(BadRequest):
     message = _("Invalid CIDR %(input)s given as IP prefix")
+
+
+class HeatClientException(TackerException):
+    message = _("%msg")

tacker/vm/drivers/heat/heat.py

@@ -21,6 +21,7 @@
 # @author: Isaku Yamahata, Intel Corporation.
 # shamelessly many codes are stolen from gbp simplechain_driver.py
 
+import sys
 import time
 import yaml
 
@@ -29,6 +30,7 @@ from heatclient import exc as heatException
 from keystoneclient.v2_0 import client as ks_client
 from oslo_config import cfg
 
+from tacker.common import exceptions
 from tacker.common import log
 from tacker.openstack.common import jsonutils
 from tacker.openstack.common import log as logging
@@ -392,7 +394,12 @@ class HeatClient:
             'disable_rollback': True})
         if 'password' in fields.get('template', {}):
             fields['password'] = fields['template']['password']
-        return self.stacks.create(**fields)
+
+        try:
+            return self.stacks.create(**fields)
+        except heatException.HTTPException:
+            type_, value, tb = sys.exc_info()
+            raise exceptions.HeatClientError(msg=value)
 
     def delete(self, stack_id):
         try:

tacker/vm/plugin.py

@@ -305,10 +305,11 @@ class ServiceVMPlugin(vm_db.ServiceResourcePluginDb, ServiceVMMgmtMixin):
                 context=context, device=device_dict)
         except Exception:
             with excutils.save_and_reraise_exception():
-                self._mark_device_error(device_id)
+                self.delete_device(context, device_id)
 
         if instance_id is None:
-            self._create_device_post(context, device_id, None, None)
+            self._create_device_post(context, device_id, None, None,
+                device_dict)
             return
 
         device_dict['instance_id'] = instance_id