Don't lard up InternalClient with extra middleware

One can argue that it makes sense for the client-facing proxy server
to have certain middlewares like gatekeeper in its pipeline, but that
is not desirable for InternalClient. In particular, it prevents you
from passing in sysmeta headers using InternalClient, and I found
myself wanting to do that earlier today.

Now InternalClient's proxy application gets exactly what's configured;
no more, no less. This will mean that the object expirer can read and
write sysmeta headers, but I think we can trust it to keep our
secrets.

Change-Id: I17b4a89c24e600754701ee1645b40406421fa6f3

swift/common/internal_client.py

@@ -134,8 +134,10 @@ class InternalClient(object):
                           gives up.
     """
 
-    def __init__(self, conf_path, user_agent, request_tries):
-        self.app = loadapp('config:' + conf_path)
+    def __init__(self, conf_path, user_agent, request_tries,
+                 allow_modify_pipeline=False):
+        self.app = loadapp('config:' + conf_path,
+                           allow_modify_pipeline=allow_modify_pipeline)
         self.user_agent = user_agent
         self.request_tries = request_tries
 

swift/common/wsgi.py

@@ -305,7 +305,7 @@ def loadcontext(object_type, uri, name=None, relative_to=None,
                                 global_conf=global_conf)
 
 
-def loadapp(conf_file, global_conf):
+def loadapp(conf_file, global_conf, allow_modify_pipeline=True):
     """
     Loads a context from a config file, and if the context is a pipeline
     then presents the app with the opportunity to modify the pipeline.
@@ -315,7 +315,7 @@ def loadapp(conf_file, global_conf):
         # give app the opportunity to modify the pipeline context
         app = ctx.app_context.create()
         func = getattr(app, 'modify_wsgi_pipeline', None)
-        if func:
+        if func and allow_modify_pipeline:
             func(PipelineWrapper(ctx))
     return ctx.create()
 

test/unit/common/test_internal_client.py

@@ -185,9 +185,10 @@ class TestInternalClient(unittest.TestCase):
                 self.conf_path = conf_path
                 self.load_called = 0
 
-            def load(self, uri):
+            def load(self, uri, allow_modify_pipeline=True):
                 self.load_called += 1
                 self.test.assertEquals('config:' + conf_path, uri)
+                self.test.assertFalse(allow_modify_pipeline)
                 return self
 
         conf_path = 'some_path'

test/unit/common/test_wsgi.py

@@ -819,6 +819,22 @@ class TestPipelineModification(unittest.TestCase):
             exp = swift.proxy.server.Application
             self.assertTrue(isinstance(app.app.app, exp), app.app.app)
 
+            # make sure you can turn off the pipeline modification if you want
+            def blow_up(*_, **__):
+                raise self.fail("needs more struts")
+
+            with mock.patch(
+                    'swift.proxy.server.Application.modify_wsgi_pipeline',
+                    blow_up):
+                app = wsgi.loadapp(conf_file, global_conf={},
+                                   allow_modify_pipeline=False)
+
+            # the pipeline was untouched
+            exp = swift.common.middleware.healthcheck.HealthCheckMiddleware
+            self.assertTrue(isinstance(app, exp), app)
+            exp = swift.proxy.server.Application
+            self.assertTrue(isinstance(app.app, exp), app.app)
+
     def test_proxy_unmodified_wsgi_pipeline(self):
         # Make sure things are sane even when we modify nothing
         config = """

test/unit/obj/test_expirer.py

@@ -46,7 +46,7 @@ class TestObjectExpirer(TestCase):
         self.old_loadapp = internal_client.loadapp
         self.old_sleep = internal_client.sleep
 
-        internal_client.loadapp = lambda x: None
+        internal_client.loadapp = lambda *a, **kw: None
         internal_client.sleep = not_sleep
 
     def teardown(self):
@@ -618,7 +618,7 @@ class TestObjectExpirer(TestCase):
             start_response('204 No Content', [('Content-Length', '0')])
             return []
 
-        internal_client.loadapp = lambda x: fake_app
+        internal_client.loadapp = lambda *a, **kw: fake_app
 
         x = expirer.ObjectExpirer({})
         ts = '1234'
@@ -635,7 +635,7 @@ class TestObjectExpirer(TestCase):
             start_response('204 No Content', [('Content-Length', '0')])
             return []
 
-        internal_client.loadapp = lambda x: fake_app
+        internal_client.loadapp = lambda *a, **kw: fake_app
 
         x = expirer.ObjectExpirer({})
         ts = '1234'
@@ -649,7 +649,7 @@ class TestObjectExpirer(TestCase):
             start_response('404 Not Found', [('Content-Length', '0')])
             return []
 
-        internal_client.loadapp = lambda x: fake_app
+        internal_client.loadapp = lambda *a, **kw: fake_app
 
         x = expirer.ObjectExpirer({})
         x.delete_actual_object('/path/to/object', '1234')
@@ -661,7 +661,7 @@ class TestObjectExpirer(TestCase):
                            [('Content-Length', '0')])
             return []
 
-        internal_client.loadapp = lambda x: fake_app
+        internal_client.loadapp = lambda *a, **kw: fake_app
 
         x = expirer.ObjectExpirer({})
         x.delete_actual_object('/path/to/object', '1234')
@@ -674,7 +674,7 @@ class TestObjectExpirer(TestCase):
                 [('Content-Length', '0')])
             return []
 
-        internal_client.loadapp = lambda x: fake_app
+        internal_client.loadapp = lambda *a, **kw: fake_app
 
         x = expirer.ObjectExpirer({})
         exc = None