From 5d857a2cad43ed2a258fdda88bfcb943f49fca17 Mon Sep 17 00:00:00 2001
From: Qiaowei Ren <qiaowei.ren@intel.com>
Date: Thu, 7 Aug 2014 10:14:53 +0800
Subject: [PATCH] XenAPI support: Changes for cpu_util

Implemented inspect_cpu_util() to inspect the CPU utilization (%)
for an instance.

Change-Id: I0cd1c926f074be632d9c5ce071dfd4d0d3ba78a7
Implements: blueprint xenapi-support
---
 ceilometer/compute/virt/xenapi/inspector.py   | 31 +++++++++++++++++++
 .../compute/virt/xenapi/test_inspector.py     | 28 +++++++++++++++++
 2 files changed, 59 insertions(+)

diff --git a/ceilometer/compute/virt/xenapi/inspector.py b/ceilometer/compute/virt/xenapi/inspector.py
index bc3e98558..6a9086495 100644
--- a/ceilometer/compute/virt/xenapi/inspector.py
+++ b/ceilometer/compute/virt/xenapi/inspector.py
@@ -22,6 +22,7 @@ try:
 except ImportError:
     api = None
 
+from ceilometer.compute.pollsters import util
 from ceilometer.compute.virt import inspector as virt_inspector
 from ceilometer.openstack.common.gettextutils import _
 
@@ -96,6 +97,18 @@ class XenapiInspector(virt_inspector.Inspector):
         for vm_ref in vms.keys():
             yield vm_ref, vms[vm_ref]
 
+    def _lookup_by_name(self, instance_name):
+        vm_refs = self._call_xenapi("VM.get_by_name_label", instance_name)
+        n = len(vm_refs)
+        if n == 0:
+            raise virt_inspector.InstanceNotFoundException(
+                _('VM %s not found in XenServer') % instance_name)
+        elif n > 1:
+            raise XenapiException(
+                _('Multiple VM %s found in XenServer') % instance_name)
+        else:
+            return vm_refs[0]
+
     def inspect_instances(self):
         for vm_ref, vm_rec in self._list_vms():
             name = vm_rec['name_label']
@@ -103,3 +116,21 @@ class XenapiInspector(virt_inspector.Inspector):
             uuid = other_config.get('nova_uuid')
             if uuid:
                 yield virt_inspector.Instance(name, uuid)
+
+    def inspect_cpu_util(self, instance, duration=None):
+        instance_name = util.instance_name(instance)
+        vm_ref = self._lookup_by_name(instance_name)
+        metrics_ref = self._call_xenapi("VM.get_metrics", vm_ref)
+        metrics_rec = self._call_xenapi("VM_metrics.get_record",
+                                        metrics_ref)
+        vcpus_number = metrics_rec['VCPUs_number']
+        vcpus_utils = metrics_rec['VCPUs_utilisation']
+        if len(vcpus_utils) == 0:
+            msg = _("Could not get VM %s CPU Utilization") % instance_name
+            raise XenapiException(msg)
+
+        utils = 0.0
+        for num in range(int(vcpus_number)):
+            utils += vcpus_utils.get(str(num))
+        utils = utils / int(vcpus_number) * 100
+        return virt_inspector.CPUUtilStats(util=utils)
diff --git a/ceilometer/tests/compute/virt/xenapi/test_inspector.py b/ceilometer/tests/compute/virt/xenapi/test_inspector.py
index 8e5c6b045..fface5635 100644
--- a/ceilometer/tests/compute/virt/xenapi/test_inspector.py
+++ b/ceilometer/tests/compute/virt/xenapi/test_inspector.py
@@ -19,6 +19,7 @@
 import mock
 from oslotest import base
 
+from ceilometer.compute.virt import inspector as virt_inspector
 from ceilometer.compute.virt.xenapi import inspector as xenapi_inspector
 
 
@@ -46,3 +47,30 @@ class TestXenapiInspection(base.BaseTestCase):
             inspected_instance = inspected_instances[0]
             self.assertEqual('fake_name', inspected_instance.name)
             self.assertEqual('fake_uuid', inspected_instance.UUID)
+
+    def test_inspect_cpu_util(self):
+        fake_instance = {'OS-EXT-SRV-ATTR:instance_name': 'fake_instance_name',
+                         'id': 'fake_instance_id'}
+        fake_stat = virt_inspector.CPUUtilStats(util=40)
+
+        def fake_xenapi_request(method, args):
+            metrics_rec = {
+                'memory_actual': '536870912',
+                'VCPUs_number': '1',
+                'VCPUs_utilisation': {'0': 0.4, }
+            }
+
+            if method == 'VM.get_by_name_label':
+                return ['vm_ref']
+            elif method == 'VM.get_metrics':
+                return 'metrics_ref'
+            elif method == 'VM_metrics.get_record':
+                return metrics_rec
+            else:
+                return None
+
+        session = self.inspector.session
+        with mock.patch.object(session, 'xenapi_request',
+                               side_effect=fake_xenapi_request):
+            cpu_util_stat = self.inspector.inspect_cpu_util(fake_instance)
+            self.assertEqual(fake_stat, cpu_util_stat)