Allow multiple session connection attempts

We have seen scenarios where users have rebooted their systems and the
ceilometer-powervm process has started before the backing PowerVM REST
server. This generally indicates a packaging issue (where the
ceilometer-powervm package should depend on the others).  However,
there is the ability in the PowerVM Session to make multiple attempts.

This change set takes advantage of the multiple attempts provided by the
pypowervm session.  That means that if the REST server is booting, the
ceilometer-powervm will wait up to 10 minutes for the REST server to
finish starting.  The REST server should start much faster than that,
and this is just an upper limit timeout.

Change-Id: If9569eccbdb9107e5892f03a91a035e1d5943e5e
Closes-Bug: 1570404

ceilometer_powervm/compute/virt/powervm/inspector.py

@@ -43,10 +43,12 @@ class PowerVMInspector(virt_inspector.Inspector):
     def __init__(self):
         super(PowerVMInspector, self).__init__()
 
-        # Build the adapter to the PowerVM API.
+        # Build the adapter.  May need to attempt the connection multiple times
+        # in case the REST server is starting.
+        session = pvm_adpt.Session(conn_tries=300)
         self.adpt = pvm_adpt.Adapter(
-            pvm_adpt.Session(), helpers=[log_hlp.log_helper,
-                                         vio_hlp.vios_busy_retry_helper])
+            session, helpers=[log_hlp.log_helper,
+                              vio_hlp.vios_busy_retry_helper])
 
         # Get the host system UUID
         host_uuid = self._get_host_uuid(self.adpt)

ceilometer_powervm/tests/compute/virt/powervm/test_inspector.py

@@ -19,12 +19,45 @@ import mock
 
 from ceilometer.compute.virt import inspector as virt_inspector
 from oslotest import base
+from pypowervm.helpers import log_helper as log_hlp
+from pypowervm.helpers import vios_busy as vio_hlp
 from pypowervm.tests import test_fixtures as api_fx
 
 from ceilometer_powervm.compute.virt.powervm import inspector as p_inspect
 from ceilometer_powervm.tests.compute.virt.powervm import pvm_fixtures
 
 
+class TestPowerVMInspectorInit(base.BaseTestCase):
+    """Tests the initialization of the VM Inspector."""
+
+    @mock.patch('pypowervm.tasks.monitor.util.LparMetricCache')
+    @mock.patch('pypowervm.tasks.monitor.util.ensure_ltm_monitors')
+    @mock.patch('ceilometer_powervm.compute.virt.powervm.inspector.'
+                'PowerVMInspector._get_host_uuid')
+    @mock.patch('pypowervm.adapter.Adapter')
+    @mock.patch('pypowervm.adapter.Session')
+    def test_init(self, mock_session, mock_adapter, mock_get_host_uuid,
+                  mock_ensure_ltm, mock_cache):
+        # Mock up data
+        mock_get_host_uuid.return_value = 'host_uuid'
+
+        # Invoke
+        inspector = p_inspect.PowerVMInspector()
+
+        # Validate
+        mock_session.assert_called_once_with(conn_tries=300)
+        mock_adapter.assert_called_once_with(
+            mock_session.return_value,
+            helpers=[log_hlp.log_helper, vio_hlp.vios_busy_retry_helper])
+
+        mock_get_host_uuid.assert_called_once_with(mock_adapter.return_value)
+        mock_ensure_ltm.assert_called_once_with(mock_adapter.return_value,
+                                                'host_uuid')
+        mock_cache.assert_called_once_with(mock_adapter.return_value,
+                                           'host_uuid')
+        self.assertEqual(mock_cache.return_value, inspector.vm_metrics)
+
+
 class TestPowerVMInspector(base.BaseTestCase):
 
     def setUp(self):