Ensure swift.source is set for DLO/SLO requests

SLO was setting it sometimes (the PUT path), but not others (the GET
path), and DLO just wasn't doing it at all. One could already
distinguish DLO/SLO internal requests by the user agent, but we should
set swift.source too.

Change-Id: I5d5b7dd49bd1522a9c830d0abd21fff92ae79a39

swift/common/middleware/dlo.py

@@ -37,6 +37,7 @@ class GetContext(WSGIContext):
                                prefix, marker=''):
         con_req = req.copy_get()
         con_req.script_name = ''
+        con_req.environ['swift.source'] = 'DLO'
         con_req.range = None
         con_req.path_info = '/'.join(['', version, account, container])
         con_req.query_string = 'format=json&prefix=%s' % quote(prefix)
@@ -197,6 +198,7 @@ class GetContext(WSGIContext):
                         app_iter=SegmentedIterable(
                             req, self.dlo.app, listing_iter,
                             ua_suffix="DLO MultipartGET",
+                            swift_source="DLO",
                             name=req.path, logger=self.logger,
                             max_get_time=self.dlo.max_get_time))
         resp.app_iter.response = resp

swift/common/middleware/slo.py

@@ -217,6 +217,7 @@ class SloGetContext(WSGIContext):
         sub_req = req.copy_get()
         sub_req.range = None
         sub_req.environ['PATH_INFO'] = '/'.join(['', version, acc, con, obj])
+        sub_req.environ['swift.source'] = 'SLO'
         sub_req.user_agent = "%s SLO MultipartGET" % sub_req.user_agent
         sub_resp = sub_req.get_response(self.slo.app)
 
@@ -346,6 +347,7 @@ class SloGetContext(WSGIContext):
 
             get_req = req.copy_get()
             get_req.range = None
+            get_req.environ['swift.source'] = 'SLO'
             get_req.user_agent = "%s SLO MultipartGET" % get_req.user_agent
             resp_iter = self._app_call(get_req.environ)
 
@@ -425,6 +427,7 @@ class SloGetContext(WSGIContext):
                                 req, self.slo.app, segment_listing_iter,
                                 name=req.path, logger=self.slo.logger,
                                 ua_suffix="SLO MultipartGET",
+                                swift_source="SLO",
                                 max_get_time=self.slo.max_get_time))
         if req.range:
             response.headers.pop('Etag')

swift/common/utils.py

@@ -2593,19 +2593,23 @@ class SegmentedIterable(object):
                          or (object-path, None, None) to fetch the whole thing.
     :param max_get_time: maximum permitted duration of a GET request (seconds)
     :param logger: logger object
+    :param swift_source: value of swift.source in subrequest environ
+                         (just for logging)
     :param ua_suffix: string to append to user-agent.
     :param name: name of manifest (used in logging only)
     :param response: optional response object for the response being sent
                      to the client. Only affects logs.
     """
     def __init__(self, req, app, listing_iter, max_get_time,
-                 logger, ua_suffix, name='<not specified>', response=None):
+                 logger, ua_suffix, swift_source,
+                 name='<not specified>', response=None):
         self.req = req
         self.app = app
         self.listing_iter = listing_iter
         self.max_get_time = max_get_time
         self.logger = logger
         self.ua_suffix = " " + ua_suffix
+        self.swift_source = swift_source
         self.name = name
         self.response = response
 
@@ -2633,6 +2637,7 @@ class SegmentedIterable(object):
                 seg_req = self.req.copy_get()
                 seg_req.range = None
                 seg_req.environ['PATH_INFO'] = seg_path
+                seg_req.environ['swift.source'] = self.swift_source
                 seg_req.user_agent = "%s %s" % (seg_req.user_agent,
                                                 self.ua_suffix)
                 if first_byte is not None or last_byte is not None:

test/unit/common/middleware/helpers.py

@@ -29,6 +29,7 @@ class FakeSwift(object):
     def __init__(self):
         self._calls = []
         self.req_method_paths = []
+        self.swift_sources = []
         self.uploaded = {}
         # mapping of (method, path) --> (response class, headers, body)
         self._responses = {}
@@ -43,6 +44,7 @@ class FakeSwift(object):
 
         headers = swob.Request(env).headers
         self._calls.append((method, path, headers))
+        self.swift_sources.append(env.get('swift.source'))
 
         try:
             resp_class, raw_headers, body = self._responses[(method, path)]

test/unit/common/middleware/test_dlo.py

@@ -292,6 +292,10 @@ class TestDloGetManifest(DloTestCase):
         self.assertFalse(
             "DLO MultipartGET" in self.app.calls_with_headers[0][2])
 
+        # we set swift.source for everything but the first request
+        self.assertEqual(self.app.swift_sources,
+                         [None, 'DLO', 'DLO', 'DLO', 'DLO', 'DLO', 'DLO'])
+
     def test_get_non_manifest_passthrough(self):
         req = swob.Request.blank('/v1/AUTH_test/c/catpicture.jpg',
                                  environ={'REQUEST_METHOD': 'GET'})

test/unit/common/middleware/test_slo.py

@@ -838,8 +838,9 @@ class TestSloGetManifest(SloTestCase):
             self.assertTrue("SLO MultipartGET" in ua)
             self.assertFalse("SLO MultipartGET SLO MultipartGET" in ua)
         # the first request goes through unaltered
+        first_ua = self.app.calls_with_headers[0][2].get("User-Agent")
         self.assertFalse(
-            "SLO MultipartGET" in self.app.calls_with_headers[0][2])
+            "SLO MultipartGET" in first_ua)
 
     def test_get_manifest_with_submanifest(self):
         req = Request.blank(
@@ -884,6 +885,9 @@ class TestSloGetManifest(SloTestCase):
         self.assertEqual(headers[3].get('Range'), None)
         self.assertEqual(headers[4].get('Range'), None)
         self.assertEqual(headers[5].get('Range'), 'bytes=0-2')
+        # we set swift.source for everything but the first request
+        self.assertEqual(self.app.swift_sources,
+                         [None, 'SLO', 'SLO', 'SLO', 'SLO', 'SLO'])
 
     def test_range_get_manifest_on_segment_boundaries(self):
         req = Request.blank(