Show proper error message if Heat is not present

Change-Id: I0cd5662aec4ad80d413782ad9830a9825c5abc64

shaker/engine/server.py

@@ -29,6 +29,7 @@ from shaker.engine import messaging
 from shaker.engine import quorum as quorum_pkg
 from shaker.engine import report
 from shaker.engine import utils
+from shaker.openstack.clients import openstack as openstack_clients
 
 
 LOG = logging.getLogger(__name__)
@@ -160,9 +161,13 @@ def play_scenario(message_queue, scenario):
                     openstack_params, cfg.CONF.flavor_name,
                     cfg.CONF.image_name, cfg.CONF.external_net,
                     cfg.CONF.dns_nameservers)
+            except openstack_clients.OpenStackClientException:
+                raise
             except Exception as e:
                 LOG.warning('Failed to connect to OpenStack: %s. Please '
                             'verify parameters: %s', e, openstack_params)
+                # try to proceed even if OpenStack connection fails
+                # (in case scenario does not need it)
 
         base_dir = os.path.dirname(scenario['file_name'])
         scenario_deployment = scenario.get('deployment', {})

shaker/openstack/clients/openstack.py

@@ -20,6 +20,10 @@ from oslo_log import log as logging
 LOG = logging.getLogger(__name__)
 
 
+class OpenStackClientException(Exception):
+    pass
+
+
 class OpenStackClient(object):
     def __init__(self, openstack_params):
         LOG.debug('Establishing connection to OpenStack')
@@ -36,6 +40,9 @@ class OpenStackClient(object):
 
         # heat client wants endpoint to be always set
         endpoint = cloud_config.get_session_endpoint('orchestration')
+        if not endpoint:
+            raise OpenStackClientException(
+                'Endpoint for orchestration service is not found')
         self.heat = cloud_config.get_legacy_client('orchestration',
                                                    endpoint=endpoint)