Improve performance of get_health for XCC

Provide a quicker health assessment for XCC.  Generally provide
a way for OEMs to replace or augment or conditionally replace the
generic behavior.

Change-Id: I54c9b9a91aabd6025d17d65846be164b87694019

pyghmi/exceptions.py

@@ -54,3 +54,9 @@ class UnsupportedFunctionality(PyghmiException):
     # Indicates when functionality is requested that is not supported by
     # current endpoint
     pass
+
+
+class BypassGenericBehavior(PyghmiException):
+    # Indicates that an OEM handler wants to abort any standards based
+    # follow up
+    pass

pyghmi/ipmi/command.py

@@ -657,10 +657,15 @@ class Command(object):
         warning, critical, or failed assessments.
         """
         summary = {'badreadings': [], 'health': const.Health.Ok}
-        for reading in self.get_sensor_data():
-            if reading.health != const.Health.Ok:
-                summary['health'] |= reading.health
-                summary['badreadings'].append(reading)
+        try:
+            self.oem_init()
+            self._oem.get_health(summary)
+            for reading in self.get_sensor_data():
+                if reading.health != const.Health.Ok:
+                    summary['health'] |= reading.health
+                    summary['badreadings'].append(reading)
+        except exc.BypassGenericBehavior:
+            pass
         return summary
 
     def get_sensor_reading(self, sensorname):

pyghmi/ipmi/oem/generic.py

@@ -265,6 +265,19 @@ class OEMHandler(object):
         """
         raise exc.UnsupportedFunctionality()
 
+    def get_health(self, summary):
+        """Provide an alternative or augmented health assessment
+
+        An OEM handler can preprocess the summary and extend it with OEM
+        specific data, and then return to let generic processing occur.
+        It can also raise the pyghmi exception BypassGenericBehavior to
+        suppress the standards based routine, for enhanced performance.
+
+        :param summary: The health summary as prepared by the generic function
+        :return: Nothing, modifies the summary object
+        """
+        return
+
     def set_alert_ipv6_destination(self, ip, destination, channel):
         """Set an IPv6 alert destination
 

pyghmi/ipmi/oem/lenovo/handler.py

@@ -923,3 +923,8 @@ class OEMHandler(generic.OEMHandler):
         if self.has_xcc:
             return self.immhandler.list_media()
         return super(OEMHandler, self).list_media()
+
+    def get_health(self, summary):
+        if self.has_xcc:
+            return self.immhandler.get_health(summary)
+        return super(OEMHandler, self).get_health(summary)

pyghmi/ipmi/oem/lenovo/imm.py

@@ -569,7 +569,7 @@ class XCCClient(IMMClient):
         super(XCCClient, self).__init__(ipmicmd)
         self.adp_referer = None
 
-    def get_webclient(self):
+    def get_webclient(self, login=True):
         cv = self.ipmicmd.certverify
         wc = webclient.SecureHTTPConnection(self.imm, 443, verifycallback=cv)
         try:
@@ -578,6 +578,8 @@ class XCCClient(IMMClient):
             if se.errno != errno.ECONNREFUSED:
                 raise
             return None
+        if not login:
+            return wc
         adata = json.dumps({'username': self.username,
                             'password': self.password
                             })
@@ -1251,3 +1253,11 @@ class XCCClient(IMMClient):
         if bank == 'backup':
             return 'complete'
         return 'pending'
+
+    def get_health(self, summary):
+        wc = self.get_webclient(False)
+        rsp = wc.grab_json_response('/api/providers/imm_active_events')
+        if 'items' in rsp and len(rsp['items']) == 0:
+            # The XCC reports healthy, no need to interrogate
+            raise pygexc.BypassGenericBehavior()
+        # Will use the generic handling for unhealthy systems