Give better output on scale failures

Currently when there's a failure during scale the output is
pprinted json that is confusing and uninstrutive

Printing the return message message attribute gives all the important
status needed from that json

Change-Id: I6e81f5812895f50209d1dc7a35c4f8fbd2447926
Partial-Bug: #1640933

tripleoclient/tests/v1/overcloud_node/test_overcloud_node.py

@@ -101,6 +101,34 @@ class TestDeleteNode(fakes.TestDeleteNode):
                 'nodes': ['instance1', ]
             })
 
+    def test_node_delete_wrong_instance(self):
+
+        argslist = ['wrong_instance', '--templates',
+                    '--stack', 'overcloud']
+        verifylist = [
+            ('stack', 'overcloud'),
+            ('nodes', ['wrong_instance']),
+        ]
+        parsed_args = self.check_parser(self.cmd, argslist, verifylist)
+
+        self.websocket.wait_for_message.return_value = {
+            "status": "FAILED",
+            "message": """Failed to run action ERROR: Couldn't find \
+                following instances in stack overcloud: wrong_instance"""
+        }
+
+        self.assertRaises(exceptions.InvalidConfiguration,
+                          self.cmd.take_action, parsed_args)
+
+        # Verify
+        self.workflow.executions.create.assert_called_once_with(
+            'tripleo.scale.v1.delete_node',
+            workflow_input={
+                'container': 'overcloud',
+                'queue_name': 'UUID4',
+                'nodes': ['wrong_instance', ]
+            })
+
 
 class TestProvideNode(fakes.TestOvercloudNode):
 

tripleoclient/workflows/scale.py

@@ -14,9 +14,9 @@
 # under the License.
 from __future__ import print_function
 
-import pprint
 import uuid
 
+from tripleoclient.exceptions import InvalidConfiguration
 from tripleoclient.workflows import base
 
 
@@ -33,8 +33,9 @@ def delete_node(clients, **workflow_input):
     )
 
     with tripleoclients.messaging_websocket(queue_name) as ws:
-        message = ws.wait_for_message(execution.id)
-        assert message['status'] == "SUCCESS", pprint.pformat(message)
+        rtn_message = ws.wait_for_message(execution.id)
+        if rtn_message['status'] != "SUCCESS":
+            raise InvalidConfiguration(rtn_message['message'])
 
 
 def scale_down(clients, plan_name, nodes, timeout=None):