Disable dashboard when Masakari is not available

Change-Id: I59d91249fe4b2036c12ecca089a61937571be201

masakaridashboard/dashboard.py

@@ -13,12 +13,17 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from oslo_log import log as logging
+
 from django.utils.translation import ugettext_lazy as _
 
 import horizon
 
+from masakaridashboard.api import api
 from masakaridashboard.default import panel
 
+LOG = logging.getLogger(__name__)
+
 
 class MasakariDashboard(horizon.Dashboard):
     slug = "masakaridashboard"
@@ -27,6 +32,23 @@ class MasakariDashboard(horizon.Dashboard):
     default_panel = 'default'
     policy_rules = (('instance-ha', 'context_is_admin'),)
 
+    def allowed(self, context):
+        # disable whole dashboard if masakari
+        # is not present in the service catalog
+        try:
+            # NOTE(pas-ha) this method tries to construct keystoneauth.Adapter
+            # for the Instance-HA service,
+            # which will fail if the service is absent
+            api.openstack_connection(context['request'])
+        except Exception as e:
+            # catch all errors and log them,
+            # no need to totally fail on e.g. HTTP connect failure
+            LOG.warning(f"Failed to find suitable endpoint for Instance HA "
+                        f"service, Masakari Dashboard will not be displayed. "
+                        f"Error was: {e}")
+            return False
+        return super().allowed(context)
+
 
 horizon.register(MasakariDashboard)
 MasakariDashboard.register(panel.Default)

masakaridashboard/test/helpers.py

@@ -13,6 +13,8 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from unittest import mock
+
 from openstack_dashboard.test import helpers
 
 from masakaridashboard.test.test_data import utils
@@ -25,4 +27,11 @@ class MasakariTestsMixin(object):
 
 
 class TestCase(MasakariTestsMixin, helpers.TestCase):
-    pass
+
+    def setUp(self):
+        allowed_patch = mock.patch(
+            "masakaridashboard.dashboard.MasakariDashboard.allowed",
+            return_value=True)
+        allowed_patch.start()
+        self.addCleanup(mock.patch.stopall)
+        super().setUp()