clean up swift middleware to avoid unicode errors

the swift middleware does not handle environment variables correctly.
this is causing ceilometer errors to be thrown in syslogs in the
check-swift-dsvm-full tests.

this patch adds in unicode support.

Closes-Bug: #1369124
Change-Id: Icf0874efcc69d9889df591b2cb4bbdd3930eaf68

ceilometer/objectstore/swift_middleware.py

@@ -43,6 +43,7 @@ from __future__ import absolute_import
 import logging
 
 from oslo.utils import timeutils
+import six
 
 from ceilometer.openstack.common import context
 from ceilometer import pipeline
@@ -145,8 +146,14 @@ class CeilometerMiddleware(object):
     def publish_sample(self, env, bytes_received, bytes_sent):
         path = env['PATH_INFO']
         method = env['REQUEST_METHOD']
-        headers = dict((header.strip('HTTP_'), env[header]) for header
+        headers = {}
-                       in env if header.startswith('HTTP_'))
+        for header in env:
+            if header.startswith('HTTP_') and env[header]:
+                key = header.strip('HTTP_')
+                if isinstance(env[header], six.text_type):
+                    headers[key] = env[header].encode('utf-8')
+                else:
+                    headers[key] = str(env[header])
 
         try:
             container = obj = None

ceilometer/tests/objectstore/test_swift_middleware.py

@@ -246,6 +246,27 @@ class TestSwiftMiddleware(tests_base.BaseTestCase):
                          data.resource_metadata['http_header_x_var2'])
         self.assertFalse('http_header_x_var3' in data.resource_metadata)
 
+    def test_metadata_headers_unicode(self):
+        app = swift_middleware.CeilometerMiddleware(FakeApp(), {
+            'metadata_headers': 'unicode'
+        })
+        uni = u'\xef\xbd\xa1\xef\xbd\xa5'
+        req = FakeRequest('/1.0/account/container',
+                          environ={'REQUEST_METHOD': 'GET'},
+                          headers={'UNICODE': uni})
+        list(app(req.environ, self.start_response))
+        samples = self.pipeline_manager.pipelines[0].samples
+        self.assertEqual(2, len(samples))
+        data = samples[0]
+        http_headers = [k for k in data.resource_metadata.keys()
+                        if k.startswith('http_header_')]
+        self.assertEqual(1, len(http_headers))
+        self.assertEqual('1.0', data.resource_metadata['version'])
+        self.assertEqual('container', data.resource_metadata['container'])
+        self.assertIsNone(data.resource_metadata['object'])
+        self.assertEqual(uni.encode('utf-8'),
+                         data.resource_metadata['http_header_unicode'])
+
     def test_metadata_headers_on_not_existing_header(self):
         app = swift_middleware.CeilometerMiddleware(FakeApp(), {
             'metadata_headers': 'x-var3'