Add support for polling performance counters of VirtualMachine objects

* New method for polling performance counters: vm.counter.get
* New method for getting all performance counters: vm.counter.all

src/vpoller/agent.py

@@ -273,6 +273,147 @@ def get_vm_property(self, msg):
                    }
 
         return result
+
+    def _get_performance_manager(self):
+        """
+        One-time method to set the PerformanceManager attribute
+
+        Useful for setting up the PerformanceManager once and avoid
+        subsequent calls for acquiring a new PerformanceManager each time
+        we need to query performance counters.
+
+        """
+        if hasattr(self, 'pm'):
+            return
+
+        self.pm = self.viserver.get_performance_manager()
+
+    def get_vm_counter(self, msg):
+        """
+        Get performance counters of an object of type VirtualMachine and return it.
+
+        Example client message to get a VM performance counter could be:
+
+            {
+                "method":     "vm.counter.get",
+                "hostname":   "vc01-test.example.org",
+                "name":       "vm01.example.org",
+                "properties": [
+                    "cpu.system",
+                    "mem.zipped"
+                ]
+            }
+        
+        Args:
+            msg (dict): The client message to process
+
+        """
+
+        #
+        # TODO: Handle collection objects as part of the returned result
+        # 
+
+        if not self.msg_is_okay(msg, ('method', 'hostname', 'name', 'properties')):
+            return { "success": -1, "msg": "Incorrect or missing message properties" }
+
+        #
+        # Performance Counter names we want to retrieve about the VirtualMachine object plus
+        # any other user-requested properties.
+        #
+        # Check the vSphere Web Services SDK API for more information on the properties
+        #
+        #     https://www.vmware.com/support/developer/vc-sdk/
+        #
+        counter_names = msg['properties']
+
+        logging.info('[%s] Retrieving %s for Virtual Machine %s', self.hostname, msg['properties'], msg['name'])
+
+        # Locate the VirtualMachine MOR for which we want to get the performance counters
+        self.update_vm_mors()
+        mor = self.mors_cache['VirtualMachine']['objects'].get(msg['name'])
+
+        if not mor:
+            return { 'success': -1, 'msg': 'Unable to find Virtual Machine %s' % msg['name'] }
+
+        self._get_performance_manager()
+
+        try:
+            result = self.pm.get_entity_statistic(entity=mor, counters=counter_names)
+        except Exception as e:
+	    logging.warning('Cannot get counters for Virtual Machine %s: %s', msg['name'], e)
+            return { 'success': -1, 'msg': 'Cannot get counters for Virtual Machine %s: %s' % (msg['name'], e) }
+
+        data = []
+
+        for eachCounter in result:
+          data.append(
+            { 'name': eachCounter.group + '.' + eachCounter.counter,
+              'counter': eachCounter.counter,
+              'group': eachCounter.group,
+              'description': eachCounter.description,
+              'unit': eachCounter.unit,
+              'group_description': eachCounter.group_description,
+              'unit_description': eachCounter.unit_description,
+              'value': eachCounter.value
+            }
+          )
+
+        result = {
+            "success": 0,
+            "msg": "Successfully retrieved counters",
+            "result": data,
+        }
+
+        return result
+
+    def get_vm_counter_all(self, msg):
+        """
+        Get all performance counters of an object of type VirtualMachine and return them.
+
+        Example client message to get all VM performance counters could be:
+
+            {
+                "method":     "vm.counter.all",
+                "hostname":   "vc01-test.example.org",
+                "name":       "vm01.example.org",
+            }
+        
+        Args:
+            msg (dict): The client message to process
+
+        """
+
+        #
+        # TODO: Handle collection objects as part of the returned result
+        # 
+
+        if not self.msg_is_okay(msg, ('method', 'hostname', 'name')):
+            return { "success": -1, "msg": "Incorrect or missing message properties" }
+
+        logging.info('[%s] Retrieving all performance counters for %s', self.hostname, msg['name'])
+
+        # Locate the VirtualMachine MOR for which we want to get the performance counters
+        self.update_vm_mors()
+        mor = self.mors_cache['VirtualMachine']['objects'].get(msg['name'])
+
+        if not mor:
+            return { 'success': -1, 'msg': 'Unable to find Virtual Machine %s' % msg['name'] }
+
+        self._get_performance_manager()
+
+        try:
+            data = self.pm.get_entity_counters(entity=mor)
+        except Exception as e:
+	    logging.warning('Cannot get counters for Virtual Machine %s: %s', msg['name'], e)
+            return { 'success': -1, 'msg': 'Cannot get counters for Virtual Machine %s: %s' % (msg['name'], e) }
+
+        result = {
+            "success": 0,
+            "msg": "Successfully retrieved counters",
+            "result": data,
+        }
+
+        return result
 
     def get_datacenter_property(self, msg):
         """
@@ -519,7 +660,6 @@ def discover_virtual_machines(self, msg):
             The returned data is a JSON object, containing the discovered Virtual Machines.
 
         """
-
         #
         # TODO: Handle collection objects as part of the returned result
         # 

src/vpoller/worker.py

@@ -298,6 +298,8 @@ def process_client_message(self, msg):
             'datastore.discover':   self.agents[vsphere_host].discover_datastores,
             'vm.get':               self.agents[vsphere_host].get_vm_property,
             'vm.discover':          self.agents[vsphere_host].discover_virtual_machines,
+            'vm.counter.get':       self.agents[vsphere_host].get_vm_counter,
+            'vm.counter.all':       self.agents[vsphere_host].get_vm_counter_all,
             'datacenter.get':       self.agents[vsphere_host].get_datacenter_property,
             'datacenter.discover':  self.agents[vsphere_host].discover_datacenters,
             'cluster.get':          self.agents[vsphere_host].get_cluster_property,