Fix UnicodeEncodeError in Ceilometer polling7.0.3

In PY3, all strings are sequences of unicode characters. In PY2,
a string may be of type str or of type unicode. Six provides
simple utilities for wrapping over differences between Python 2
and Python 3.[1] So using six.text_type instead of str to be more
compatible.
Python 2.x automatically encode the unicode with sys.getdefaultencoding(),
which is usually 'ascii'. If there are some non-ASCII characters, it can
raise UnicodeeEncodeError. Add a unit test that use unicode string to test
PartitionCoordinator to check if there have the same error in the bug.

[1] https://pythonhosted.org/six/#six.text_type

Change-Id: Ic52c805b81e53a632a61ddcd3e8652b5849d913d
Closes-Bug: #1621305
(cherry picked from commit e3752c1e485f885d982725e3c6ece2eb6f2bdc36)

3 files changed, 27 insertions, 4 deletions

diff --git a/ceilometer/coordination.py b/ceilometer/coordination.py
index 59616220..89a84bc0 100644
--- a/ceilometer/coordination.py
+++ b/ceilometer/coordination.py
@@ -13,6 +13,7 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
+import six
 import uuid
 
 from oslo_config import cfg
@@ -224,9 +225,10 @@ class PartitionCoordinator(object):
             hr = utils.HashRing(members)
             iterable = list(iterable)
             filtered = [v for v in iterable
-                        if hr.get_node(str(v)) == self._my_id]
+                        if hr.get_node(six.text_type(v)) == self._my_id]
             LOG.debug('The universal set: %s, my subset: %s',
-                      [str(f) for f in iterable], [str(f) for f in filtered])
+                      [six.text_type(f) for f in iterable],
+                      [six.text_type(f) for f in filtered])
             return filtered
         except tooz.coordination.ToozError:
             LOG.exception(_LE('Error getting group membership info from '
diff --git a/ceilometer/tests/unit/test_coordination.py b/ceilometer/tests/unit/test_coordination.py
index 966946b1..5f7684d3 100644
--- a/ceilometer/tests/unit/test_coordination.py
+++ b/ceilometer/tests/unit/test_coordination.py
@@ -281,3 +281,23 @@ class TestPartitioning(base.BaseTestCase):
         coord.stop()
         self.assertIsEmpty(coord._groups)
         self.assertIsNone(coord._coordinator)
+
+    def test_partitioning_with_unicode(self):
+        all_resources = [u'\u0634\u0628\u06a9\u0647',
+                         u'\u0627\u0647\u0644',
+                         u'\u0645\u062d\u0628\u0627\u0646']
+        agents = ['agent_%s' % i for i in range(2)]
+
+        expected_resources = [list() for _ in range(len(agents))]
+        hr = utils.HashRing(agents)
+        for r in all_resources:
+            key = agents.index(hr.get_node(r))
+            expected_resources[key].append(r)
+
+        agents_kwargs = []
+        for i, agent in enumerate(agents):
+            agents_kwargs.append(dict(agent_id=agent,
+                                 group_id='group',
+                                 all_resources=all_resources,
+                                 expected_resources=expected_resources[i]))
+        self._usage_simulation(*agents_kwargs)
diff --git a/ceilometer/utils.py b/ceilometer/utils.py
index 544d5523..5fe3a93f 100644
--- a/ceilometer/utils.py
+++ b/ceilometer/utils.py
@@ -76,7 +76,7 @@ def decode_unicode(input):
         # the tuple would become list. So we have to generate the value as
         # list here.
         return [decode_unicode(element) for element in input]
-    elif six.PY2 and isinstance(input, six.text_type):
+    elif isinstance(input, six.text_type):
         return input.encode('utf-8')
     elif six.PY3 and isinstance(input, six.binary_type):
         return input.decode('utf-8')
@@ -237,7 +237,8 @@ class HashRing(object):
     @staticmethod
     def _hash(key):
         return struct.unpack_from('>I',
-                                  hashlib.md5(str(key).encode()).digest())[0]
+                                  hashlib.md5(decode_unicode(six
+                                              .text_type(key))).digest())[0]
 
     def _get_position_on_ring(self, key):
         hashed_key = self._hash(key)