Add get_datastore_by_ref method to oslo.vmware

Two methods are added as part of this patch:-

1. get_datastore_by_ref - returns a Datastore object given a
datastore reference.

2. get_object_properties_dict - a vim utility method to retrieve
properties of an object as a dictionary.

Currently, Glance needs these methods to find datastore
objects from datastore references.

Change-Id: I516536ea4098357540531105b4f97e6668fb3f08

4 files changed, 112 insertions, 0 deletions

diff --git a/oslo_vmware/objects/datastore.py b/oslo_vmware/objects/datastore.py
index 3d0188f..dd3b7b9 100644
--- a/oslo_vmware/objects/datastore.py
+++ b/oslo_vmware/objects/datastore.py
@@ -28,6 +28,30 @@ LOG = logging.getLogger(__name__)
 random = _random.SystemRandom()
 
 
+def get_datastore_by_ref(session, ds_ref):
+    """Returns a datastore object for a given reference.
+
+    :param session: a vmware api session object
+    :param ds_ref: managed object reference of a datastore
+    :rtype : a datastore object
+    """
+    lst_properties = ["summary.type",
+                      "summary.name",
+                      "summary.capacity",
+                      "summary.freeSpace"]
+    props = session.invoke_api(
+        vim_util,
+        "get_object_properties_dict",
+        session.vim,
+        ds_ref,
+        lst_properties)
+    # TODO(sabari): Instantiate with datacenter info.
+    return Datastore(ds_ref, props["summary.name"],
+                     capacity=props.get("summary.capacity"),
+                     freespace=props.get("summary.freeSpace"),
+                     type=props.get("summary.type"))
+
+
 class Datastore(object):
 
     def __init__(self, ref, name, capacity=None, freespace=None,
diff --git a/oslo_vmware/vim_util.py b/oslo_vmware/vim_util.py
index fd43ab5..4631d7e 100644
--- a/oslo_vmware/vim_util.py
+++ b/oslo_vmware/vim_util.py
@@ -17,9 +17,15 @@
 The VMware API utility module.
 """
 
+import logging
+
 from suds import sudsobject
 
 from oslo.utils import timeutils
+from oslo_vmware._i18n import _LW
+
+
+LOG = logging.getLogger(__name__)
 
 
 def get_moref(value, type_):
@@ -316,6 +322,36 @@ def get_object_properties(vim, moref, properties_to_collect):
     return retrieve_result.objects
 
 
+def get_object_properties_dict(vim, moref, properties_to_collect):
+    """Get properties of the given managed object as a dict.
+
+    :param vim: Vim object
+    :param moref: managed object reference
+    :param properties_to_collect: names of the managed object properties to be
+                                  collected
+    :returns: a dict of properties of the given managed object
+    :raises: VimException, VimFaultException, VimAttributeException,
+             VimSessionOverLoadException, VimConnectionException
+    """
+    obj_contents = get_object_properties(vim, moref, properties_to_collect)
+    if obj_contents is None:
+        return {}
+    property_dict = {}
+    if hasattr(obj_contents[0], 'propSet'):
+        dynamic_properties = obj_contents[0].propSet
+        if dynamic_properties:
+            for prop in dynamic_properties:
+                property_dict[prop.name] = prop.val
+    # The object may have information useful for logging
+    if hasattr(obj_contents[0], 'missingSet'):
+        for m in obj_contents[0].missingSet:
+            LOG.warning(_LW("Unable to retrieve value for %(path)s "
+                            "Reason: %(reason)s"),
+                        {'path': m.path,
+                         'reason': m.fault.localizedMessage})
+    return property_dict
+
+
 def _get_token(retrieve_result):
     """Get token from result to obtain next set of results.
 
diff --git a/tests/objects/test_datastore.py b/tests/objects/test_datastore.py
index 2d66ccf..aa88a22 100644
--- a/tests/objects/test_datastore.py
+++ b/tests/objects/test_datastore.py
@@ -383,3 +383,18 @@ class DatastoreURLTestCase(base.TestCase):
         ticket = ds_url.get_transfer_ticket(session, 'PUT')
         self.assertEqual('%s="%s"' % (constants.CGI_COOKIE_KEY, 'fake_id'),
                          ticket)
+
+    def test_get_datastore_by_ref(self):
+        session = mock.Mock()
+        ds_ref = mock.Mock()
+        expected_props = {'summary.name': 'datastore1',
+                          'summary.type': 'NFS',
+                          'summary.freeSpace': 1000,
+                          'summary.capacity': 2000}
+        session.invoke_api = mock.Mock()
+        session.invoke_api.return_value = expected_props
+        ds_obj = datastore.get_datastore_by_ref(session, ds_ref)
+        self.assertEqual(expected_props['summary.name'], ds_obj.name)
+        self.assertEqual(expected_props['summary.type'], ds_obj.type)
+        self.assertEqual(expected_props['summary.freeSpace'], ds_obj.freespace)
+        self.assertEqual(expected_props['summary.capacity'], ds_obj.capacity)
diff --git a/tests/test_vim_util.py b/tests/test_vim_util.py
index 44b6526..b19cd48 100644
--- a/tests/test_vim_util.py
+++ b/tests/test_vim_util.py
@@ -253,6 +253,43 @@ class VimUtilTest(base.TestCase):
         self.assertTrue(res is retrieve_result.objects)
         cancel_retrieval.assert_called_once_with(vim, retrieve_result)
 
+    @mock.patch('oslo_vmware.vim_util.get_object_properties')
+    def test_get_object_properties_dict_empty(self, mock_obj_prop):
+        mock_obj_prop.return_value = None
+        vim = mock.Mock()
+        moref = mock.Mock()
+        res = vim_util.get_object_properties_dict(vim, moref, None)
+        self.assertEqual({}, res)
+
+    @mock.patch('oslo_vmware.vim_util.get_object_properties')
+    def test_get_object_properties_dict(self, mock_obj_prop):
+        expected_prop_dict = {'name': 'vm01'}
+        mock_obj_content = mock.Mock()
+        prop = mock.Mock()
+        prop.name = "name"
+        prop.val = "vm01"
+        mock_obj_content.propSet = [prop]
+        del mock_obj_content.missingSet
+        mock_obj_prop.return_value = [mock_obj_content]
+        vim = mock.Mock()
+        moref = mock.Mock()
+        res = vim_util.get_object_properties_dict(vim, moref, None)
+        self.assertEqual(expected_prop_dict, res)
+
+    @mock.patch('oslo_vmware.vim_util.get_object_properties')
+    def test_get_object_properties_dict_missing(self, mock_obj_prop):
+        mock_obj_content = mock.Mock()
+        missing_prop = mock.Mock()
+        missing_prop.path = "name"
+        missing_prop.fault = mock.Mock()
+        mock_obj_content.missingSet = [missing_prop]
+        del mock_obj_content.propSet
+        mock_obj_prop.return_value = [mock_obj_content]
+        vim = mock.Mock()
+        moref = mock.Mock()
+        res = vim_util.get_object_properties_dict(vim, moref, None)
+        self.assertEqual({}, res)
+
     @mock.patch('oslo_vmware.vim_util._get_token')
     def test_cancel_retrieval(self, get_token):
         token = mock.Mock()