XenAPI support: List the instances

1) Added XenAPI inspector.
2) Implemented inspect_instances() to list the instances on the XenServer host.

Change-Id: I1f6e33696770ec2f4e5cbb2e54e29991978aed32
Implements: blueprint xenapi-support

ceilometer/compute/virt/xenapi/inspector.py

@@ -0,0 +1,105 @@
+# Copyright 2014 Intel
+#
+# Author: Ren Qiaowei <qiaowei.ren@intel.com>
+#
+# 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.
+"""Implementation of Inspector abstraction for XenAPI."""
+
+from eventlet import timeout
+from oslo.config import cfg
+try:
+    import XenAPI as api
+except ImportError:
+    api = None
+
+from ceilometer.compute.virt import inspector as virt_inspector
+from ceilometer.openstack.common.gettextutils import _
+
+opt_group = cfg.OptGroup(name='xenapi',
+                         title='Options for XenAPI')
+
+xenapi_opts = [
+    cfg.StrOpt('connection_url',
+               help='URL for connection to XenServer/Xen Cloud Platform'),
+    cfg.StrOpt('connection_username',
+               default='root',
+               help='Username for connection to XenServer/Xen Cloud Platform'),
+    cfg.StrOpt('connection_password',
+               help='Password for connection to XenServer/Xen Cloud Platform',
+               secret=True),
+    cfg.IntOpt('login_timeout',
+               default=10,
+               help='Timeout in seconds for XenAPI login.'),
+]
+
+CONF = cfg.CONF
+CONF.register_group(opt_group)
+CONF.register_opts(xenapi_opts, group=opt_group)
+
+
+class XenapiException(virt_inspector.InspectorException):
+    pass
+
+
+def get_api_session():
+    if not api:
+        raise ImportError(_('XenAPI not installed'))
+
+    url = CONF.xenapi.connection_url
+    username = CONF.xenapi.connection_username
+    password = CONF.xenapi.connection_password
+    if not url or password is None:
+        raise XenapiException(_('Must specify connection_url, and '
+                                'connection_password to use'))
+
+    exception = api.Failure(_("Unable to log in to XenAPI "
+                              "(is the Dom0 disk full?)"))
+    try:
+        session = api.Session(url)
+        with timeout.Timeout(CONF.xenapi.login_timeout, exception):
+            session.login_with_password(username, password)
+    except api.Failure as e:
+        msg = _("Could not connect to XenAPI: %s") % e.details[0]
+        raise XenapiException(msg)
+    return session
+
+
+class XenapiInspector(virt_inspector.Inspector):
+
+    def __init__(self):
+        super(XenapiInspector, self).__init__()
+        self.session = get_api_session()
+
+    def _get_host_ref(self):
+        """Return the xenapi host on which nova-compute runs on."""
+        return self.session.xenapi.session.get_this_host(self.session.handle)
+
+    def _call_xenapi(self, method, *args):
+        return self.session.xenapi_request(method, args)
+
+    def _list_vms(self):
+        host_ref = self._get_host_ref()
+        vms = self._call_xenapi("VM.get_all_records_where",
+                                'field "is_control_domain"="false" and '
+                                'field "is_a_template"="false" and '
+                                'field "resident_on"="%s"' % host_ref)
+        for vm_ref in vms.keys():
+            yield vm_ref, vms[vm_ref]
+
+    def inspect_instances(self):
+        for vm_ref, vm_rec in self._list_vms():
+            name = vm_rec['name_label']
+            other_config = vm_rec['other_config']
+            uuid = other_config.get('nova_uuid')
+            if uuid:
+                yield virt_inspector.Instance(name, uuid)

ceilometer/tests/compute/virt/xenapi/test_inspector.py

@@ -0,0 +1,48 @@
+# Copyright 2014 Intel
+#
+# Author: Ren Qiaowei <qiaowei.ren@intel.com>
+#
+# 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.
+"""Tests for xenapi inspector.
+"""
+
+import mock
+from oslotest import base
+
+from ceilometer.compute.virt.xenapi import inspector as xenapi_inspector
+
+
+class TestXenapiInspection(base.BaseTestCase):
+
+    def setUp(self):
+        api_session = mock.Mock()
+        xenapi_inspector.get_api_session = mock.Mock(return_value=api_session)
+        self.inspector = xenapi_inspector.XenapiInspector()
+
+        super(TestXenapiInspection, self).setUp()
+
+    def test_inspect_instances(self):
+        vms = {
+            'ref': {
+                'name_label': 'fake_name',
+                'other_config': {'nova_uuid': 'fake_uuid', },
+            }
+        }
+
+        session = self.inspector.session
+        with mock.patch.object(session, 'xenapi_request',
+                               return_value=vms):
+            inspected_instances = list(self.inspector.inspect_instances())
+            inspected_instance = inspected_instances[0]
+            self.assertEqual('fake_name', inspected_instance.name)
+            self.assertEqual('fake_uuid', inspected_instance.UUID)

setup.cfg

@@ -199,6 +199,7 @@ ceilometer.compute.virt =
     libvirt = ceilometer.compute.virt.libvirt.inspector:LibvirtInspector
     hyperv = ceilometer.compute.virt.hyperv.inspector:HyperVInspector
     vsphere = ceilometer.compute.virt.vmware.inspector:VsphereInspector
+    xenapi = ceilometer.compute.virt.xenapi.inspector:XenapiInspector
 
 ceilometer.hardware.inspectors =
     snmp = ceilometer.hardware.inspector.snmp:SNMPInspector