Make XenServer VM diagnostics available through nova.virt.xenapi.

nova/virt/xenapi/vm_utils.py

@@ -20,15 +20,21 @@ their attributes like VDIs, VIFs, as well as their lookup functions.
 """
 
 import logging
+import urllib
 
 from twisted.internet import defer
+from xml.dom import minidom
 
+from nova import flags
 from nova import utils
+
 from nova.auth.manager import AuthManager
 from nova.compute import instance_types
 from nova.compute import power_state
 from nova.virt import images
 
+FLAGS = flags.FLAGS
+
 XENAPI_POWER_STATE = {
     'Halted': power_state.SHUTDOWN,
     'Running': power_state.RUNNING,
@@ -44,6 +50,15 @@ class VMHelper():
     The class that wraps the helper methods together.
     """
     def __init__(self):
+        return
+
+    @classmethod
+    def late_import(cls):
+        """
+        Load the XenAPI module in for helper class, if required.
+        This is to avoid to install the XenAPI library when other
+        hypervisors are used
+        """
         global XenAPI
         if XenAPI is None:
             XenAPI = __import__('XenAPI')
@@ -214,3 +229,40 @@ class VMHelper():
                 'mem': long(record['memory_dynamic_max']) >> 10,
                 'num_cpu': record['VCPUs_max'],
                 'cpu_time': 0}
+
+    @classmethod
+    def compile_diagnostics(cls, session, record):
+        """Compile VM diagnostics data"""
+        try:
+            host = session.get_xenapi_host()
+            host_ip = session.get_xenapi().host.get_record(host)["address"]
+            metrics = session.get_xenapi().VM_guest_metrics.get_record(
+                record["guest_metrics"])
+            diags = {
+                "Kernel": metrics["os_version"]["uname"],
+                "Distro": metrics["os_version"]["name"]}
+            xml = get_rrd(host_ip, record["uuid"])
+            if xml:
+                rrd = minidom.parseString(xml)
+                for i, node in enumerate(rrd.firstChild.childNodes):
+                    # We don't want all of the extra garbage
+                    if i >= 3 and i <= 11:
+                        ref = node.childNodes
+                        # Name and Value
+                        diags[ref[0].firstChild.data] = ref[6].firstChild.data
+            return diags
+        except XenAPI.Failure as e:
+            return {"Unable to retrieve diagnostics": e}
+
+
+def get_rrd(host, uuid):
+    """Return the VM RRD XML as a string"""
+    try:
+        xml = urllib.urlopen("http://%s:%s@%s/vm_rrd?uuid=%s" % (
+            FLAGS.xenapi_connection_username,
+            FLAGS.xenapi_connection_password,
+            host,
+            uuid))
+        return xml.read()
+    except IOError:
+        return None

nova/virt/xenapi/vmops.py

@@ -24,6 +24,7 @@ from twisted.internet import defer
 
 from nova import db
 from nova import context
+
 from nova.auth.manager import AuthManager
 from nova.virt.xenapi.network_utils import NetworkHelper
 from nova.virt.xenapi.vm_utils import VMHelper
@@ -40,6 +41,8 @@ class VMOps(object):
         if XenAPI is None:
             XenAPI = __import__('XenAPI')
         self._session = session
+        # Load XenAPI module in the helper class
+        VMHelper.late_import()
 
     def list_instances(self):
         """ List VM instances """
@@ -128,6 +131,15 @@ class VMOps(object):
         rec = self._session.get_xenapi().VM.get_record(vm)
         return VMHelper.compile_info(rec)
 
+    @defer.inlineCallbacks
+    def get_diagnostics(self, instance_id):
+        """Return data about VM diagnostics"""
+        vm = yield VMHelper.lookup(self._session, instance_id)
+        if vm is None:
+            raise Exception("instance not present %s" % instance_id)
+        rec = yield self._session.get_xenapi().VM.get_record(vm)
+        defer.returnValue(VMHelper.compile_diagnostics(self._session, rec))
+
     def get_console_output(self, instance):
         """ Return snapshot of console """
         # TODO: implement this to fix pylint!

nova/virt/xenapi_conn.py

@@ -126,6 +126,10 @@ class XenAPIConnection(object):
         """ Return data about VM instance """
         return self._vmops.get_info(instance_id)
 
+    def get_diagnostics(self, instance_id):
+        """Return data about VM diagnostics"""
+        return self._vmops.get_diagnostics(instance_id)
+
     def get_console_output(self, instance):
         """ Return snapshot of console """
         return self._vmops.get_console_output(instance)