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)

1 files changed, 3 insertions, 2 deletions

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)