Add system metrics for RSD 2.2

RSD 2.2 add more metrics information for System resource in URI
/redfish/v1/Systems/{systemID}/Metrics. Added corresponding interface
to retrieve such information back.

Change-Id: Iba7d9a164a12805e1e4c325bcc8f7815806ea306

rsd_lib/resources/v2_2/system/metrics.py

@@ -0,0 +1,51 @@
+# Copyright 2018 Intel, Inc.
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+from sushy.resources import base
+
+
+class Metrics(base.ResourceBase):
+    name = base.Field('Name')
+    """The metrics name"""
+
+    description = base.Field('Description')
+    """The metrics description"""
+
+    identity = base.Field('Id')
+    """The metrics identity"""
+
+    processor_bandwidth_percent = base.Field('ProcessorBandwidthPercent',
+                                             adapter=int)
+    """The processor bandwidth percent"""
+
+    memory_bandwidth_percent = base.Field('MemoryBandwidthPercent',
+                                          adapter=int)
+    """The memory bandwidth percent"""
+
+    memory_throttled_cycles_percent = base.Field(
+        'MemoryThrottledCyclesPercent', adapter=int)
+    """The memory throttled cycles percent"""
+
+    processor_power_watt = base.Field('ProcessorPowerWatt', adapter=int)
+    """The processor power watt"""
+
+    memory_power_watt = base.Field('MemoryPowerWatt', adapter=int)
+    """The memory power watt"""
+
+    io_bandwidth_gbps = base.Field('IOBandwidthGBps', adapter=int)
+    """The io bandwidth GBps"""
+
+    health = base.Field('Health', adapter=list)
+    """The detail health information"""

rsd_lib/resources/v2_2/system/system.py

@@ -0,0 +1,51 @@
+# Copyright 2018 Intel, Inc.
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+from sushy import exceptions
+from sushy.resources.system import system
+
+from rsd_lib.resources.v2_2.system import metrics
+from rsd_lib import utils
+
+
+class System(system.System):
+
+    _metrics = None  # ref to System instance
+
+    def _get_metrics_path(self):
+        """Helper function to find the System path"""
+        system_col = self.json.get('Oem').get('Intel_RackScale').get('Metrics')
+        if not system_col:
+            raise exceptions.MissingAttributeError(attribute='Metrics',
+                                                   resource=self._path)
+        return utils.get_resource_identity(system_col)
+
+    @property
+    def metrics(self):
+        """Property to provide reference to `Metrics` instance
+
+        It is calculated once the first time it is queried. On refresh,
+        this property is reset.
+        """
+        if self._metrics is None:
+            self._metrics = metrics.Metrics(
+                self._conn, self._get_metrics_path(),
+                redfish_version=self.redfish_version)
+
+        return self._metrics
+
+    def refresh(self):
+        super(System, self).refresh()
+        self._metrics = None