While we currently trap JSON encoding exceptions and bail out, for error notification it's more important that *some* form of the message gets out. So, we take complex notification payloads and convert them to something we know can be expressed in JSON.

3 files changed, 137 insertions, 19 deletions

diff --git a/nova/notifier/api.py b/nova/notifier/api.py
index 98969fd3e..e18f3e280 100644
--- a/nova/notifier/api.py
+++ b/nova/notifier/api.py
@@ -80,6 +80,10 @@ def notify(publisher_id, event_type, priority, payload):
     if priority not in log_levels:
         raise BadPriorityException(
                  _('%s not in valid priorities' % priority))
+
+    # Ensure everything is JSON serializable.
+    payload = utils.to_primitive(payload, convert_instances=True)
+
     driver = utils.import_object(FLAGS.notification_driver)
     msg = dict(message_id=str(uuid.uuid4()),
                    publisher_id=publisher_id,
diff --git a/nova/tests/test_utils.py b/nova/tests/test_utils.py
index 0c359e981..ec5098a37 100644
--- a/nova/tests/test_utils.py
+++ b/nova/tests/test_utils.py
@@ -14,6 +14,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+import datetime
 import os
 import tempfile
 
@@ -306,3 +307,80 @@ class IsUUIDLikeTestCase(test.TestCase):
     def test_non_uuid_string_passed(self):
         val = 'foo-fooo'
         self.assertUUIDLike(val, False)
+
+
+class ToPrimitiveTestCase(test.TestCase):
+    def test_list(self):
+        self.assertEquals(utils.to_primitive([1, 2, 3]), [1, 2, 3])
+
+    def test_empty_list(self):
+        self.assertEquals(utils.to_primitive([]), [])
+
+    def test_tuple(self):
+        self.assertEquals(utils.to_primitive((1, 2, 3)), [1, 2, 3])
+
+    def test_dict(self):
+        self.assertEquals(utils.to_primitive(dict(a=1, b=2, c=3)),
+                          dict(a=1, b=2, c=3))
+
+    def test_empty_dict(self):
+        self.assertEquals(utils.to_primitive({}), {})
+
+    def test_datetime(self):
+        x = datetime.datetime(1, 2, 3, 4, 5, 6, 7)
+        self.assertEquals(utils.to_primitive(x), "0001-02-03 04:05:06.000007")
+
+    def test_iter(self):
+        class IterClass(object):
+            def __init__(self):
+                self.data = [1, 2, 3, 4, 5]
+                self.index = 0
+
+            def __iter__(self):
+                return self
+
+            def next(self):
+                if self.index == len(self.data):
+                    raise StopIteration
+                self.index = self.index + 1
+                return self.data[self.index - 1]
+
+        x = IterClass()
+        self.assertEquals(utils.to_primitive(x), [1, 2, 3, 4, 5])
+
+    def test_iteritems(self):
+        class IterItemsClass(object):
+            def __init__(self):
+                self.data = dict(a=1, b=2, c=3).items()
+                self.index = 0
+
+            def __iter__(self):
+                return self
+
+            def next(self):
+                if self.index == len(self.data):
+                    raise StopIteration
+                self.index = self.index + 1
+                return self.data[self.index - 1]
+
+        x = IterItemsClass()
+        ordered = utils.to_primitive(x)
+        ordered.sort()
+        self.assertEquals(ordered, [['a', 1], ['b', 2], ['c', 3]])
+
+    def test_instance(self):
+        class MysteryClass(object):
+            a = 10
+
+            def __init__(self):
+                self.b = 1
+
+        x = MysteryClass()
+        self.assertEquals(utils.to_primitive(x, convert_instances=True),
+                          dict(b=1))
+
+        self.assertEquals(utils.to_primitive(x), x)
+
+    def test_typeerror(self):
+        x = bytearray  # Class, not instance
+        self.assertEquals(utils.to_primitive(x), u"<type 'bytearray'>")
diff --git a/nova/utils.py b/nova/utils.py
index 737903f81..4ea623cc1 100644
--- a/nova/utils.py
+++ b/nova/utils.py
@@ -513,25 +513,61 @@ def utf8(value):
     return value
 
 
-def to_primitive(value):
-    if type(value) is type([]) or type(value) is type((None,)):
-        o = []
-        for v in value:
-            o.append(to_primitive(v))
-        return o
-    elif type(value) is type({}):
-        o = {}
-        for k, v in value.iteritems():
-            o[k] = to_primitive(v)
-        return o
-    elif isinstance(value, datetime.datetime):
-        return str(value)
-    elif hasattr(value, 'iteritems'):
-        return to_primitive(dict(value.iteritems()))
-    elif hasattr(value, '__iter__'):
-        return to_primitive(list(value))
-    else:
-        return value
+def to_primitive(value, convert_instances=False, level=0):
+    """Convert a complex object into primitives.
+
+    Handy for JSON serialization. We can optionally handle instances,
+    but since this is a recursive function, we could have cyclical
+    data structures.
+
+    To handle cyclical data structures we could track the actual objects
+    visited in a set, but not all objects are hashable. Instead we just
+    track the depth of the object inspections and don't go too deep.
+
+    Therefore, convert_instances=True is lossy ... be aware.
+
+    """
+    if inspect.isclass(value):
+        return unicode(value)
+
+    if level > 3:
+        return []
+
+    # The try block may not be necessary after the class check above,
+    # but just in case ...
+    try:
+        if type(value) is type([]) or type(value) is type((None,)):
+            o = []
+            for v in value:
+                o.append(to_primitive(v, convert_instances=convert_instances,
+                                      level=level))
+            return o
+        elif type(value) is type({}):
+            o = {}
+            for k, v in value.iteritems():
+                o[k] = to_primitive(v, convert_instances=convert_instances,
+                                    level=level)
+            return o
+        elif isinstance(value, datetime.datetime):
+            return str(value)
+        elif hasattr(value, 'iteritems'):
+            return to_primitive(dict(value.iteritems()),
+                                convert_instances=convert_instances,
+                                level=level)
+        elif hasattr(value, '__iter__'):
+            return to_primitive(list(value), level)
+        elif convert_instances and hasattr(value, '__dict__'):
+            # Likely an instance of something. Watch for cycles.
+            # Ignore class member vars.
+            return to_primitive(value.__dict__,
+                                convert_instances=convert_instances,
+                                level=level + 1)
+        else:
+            return value
+    except TypeError, e:
+        # Class objects are tricky since they may define something like
+        # __iter__ defined but it isn't callable as list().
+        return unicode(value)
 
 
 def dumps(value):