Restore backward compat of paste factory

Some application inherits from our middleware class

When we homogenize the signature and configuration handling
of all middlewares we break them.

This change fixes that.

Closes-bug: #1486735

Change-Id: I40c3d59110c6f8c5a1b3d3ccc734dc441069b025

oslo_middleware/base.py

@@ -21,7 +21,7 @@ import webob.dec
 from oslo_config import cfg
 
 
-class Middleware(object):
+class ConfigurableMiddleware(object):
     """Base WSGI middleware wrapper.
 
     These classes require an application to be initialized that will be called
@@ -41,14 +41,19 @@ class Middleware(object):
         return middleware_filter
 
     def __init__(self, application, conf=None):
+        """Base middleware constructor
+
+        :param  conf: a dict of options or a cfg.ConfigOpts object
+        """
         self.application = application
+
         # NOTE(sileht): If the configuration come from oslo.config
         # just use it.
         if isinstance(conf, cfg.ConfigOpts):
-            self.conf = []
+            self.conf = {}
             self.oslo_conf = conf
         else:
-            self.conf = conf or []
+            self.conf = conf or {}
             if "oslo_config_project" in self.conf:
                 if 'oslo_config_file' in self.conf:
                     default_config_files = [self.conf['oslo_config_file']]
@@ -96,3 +101,16 @@ class Middleware(object):
         if 'request' in args:
             return self.process_response(response, request=req)
         return self.process_response(response)
+
+
+class Middleware(ConfigurableMiddleware):
+    """Legacy base WSGI middleware wrapper.
+
+    Legacy interface that doesn't pass configuration options
+    to the middleware when it's loaded via paste.deploy.
+    """
+
+    @classmethod
+    def factory(cls, global_conf, **local_conf):
+        """Factory method for paste.deploy."""
+        return cls

oslo_middleware/catch_errors.py

@@ -25,7 +25,7 @@ from oslo_middleware import base
 LOG = logging.getLogger(__name__)
 
 
-class CatchErrors(base.Middleware):
+class CatchErrors(base.ConfigurableMiddleware):
     """Middleware that provides high-level error handling.
 
     It catches all exceptions from subsequent applications in WSGI pipeline

oslo_middleware/correlation_id.py

@@ -18,7 +18,7 @@ import uuid
 from oslo_middleware import base
 
 
-class CorrelationId(base.Middleware):
+class CorrelationId(base.ConfigurableMiddleware):
     "Middleware that attaches a correlation id to WSGI request"
 
     def process_request(self, req):

oslo_middleware/cors.py

@@ -53,7 +53,7 @@ CORS_OPTS = [
 ]
 
 
-class CORS(base.Middleware):
+class CORS(base.ConfigurableMiddleware):
     """CORS Middleware.
 
     This middleware allows a WSGI app to serve CORS headers for multiple
@@ -71,8 +71,8 @@ class CORS(base.Middleware):
         'Pragma'
     ]
 
-    def __init__(self, application, conf=None):
-        super(CORS, self).__init__(application, conf)
+    def __init__(self, application, *args, **kwargs):
+        super(CORS, self).__init__(application, *args, **kwargs)
         # Begin constructing our configuration hash.
         self.allowed_origins = {}
         self._init_conf()

oslo_middleware/debug.py

@@ -25,7 +25,7 @@ import webob.dec
 from oslo_middleware import base
 
 
-class Debug(base.Middleware):
+class Debug(base.ConfigurableMiddleware):
     """Helper class that returns debug information.
 
     Can be inserted into any WSGI application chain to get information about

oslo_middleware/healthcheck/__init__.py

@@ -21,7 +21,7 @@ import webob.response
 from oslo_middleware import base
 
 
-class Healthcheck(base.Middleware):
+class Healthcheck(base.ConfigurableMiddleware):
     """Healthcheck middleware used for monitoring.
 
     If the path is /healthcheck, it will respond 200 with "OK" as the body.

oslo_middleware/request_id.py

@@ -23,7 +23,7 @@ ENV_REQUEST_ID = 'openstack.request_id'
 HTTP_RESP_HEADER_REQUEST_ID = 'x-openstack-request-id'
 
 
-class RequestId(base.Middleware):
+class RequestId(base.ConfigurableMiddleware):
     """Middleware that ensures request ID.
 
     It ensures to assign request ID for each API request and set it to

oslo_middleware/sizelimit.py

@@ -75,7 +75,7 @@ class LimitingReader(object):
         return result
 
 
-class RequestBodySizeLimiter(base.Middleware):
+class RequestBodySizeLimiter(base.ConfigurableMiddleware):
     """Limit the size of incoming requests."""
 
     def __init__(self, application, conf=None):

oslo_middleware/ssl.py

@@ -23,7 +23,7 @@ OPTS = [
 ]
 
 
-class SSLMiddleware(base.Middleware):
+class SSLMiddleware(base.ConfigurableMiddleware):
     """SSL termination proxies middleware.
 
     This middleware overloads wsgi.url_scheme with the one provided in
@@ -31,8 +31,8 @@ class SSLMiddleware(base.Middleware):
     termination proxy.
     """
 
-    def __init__(self, application, conf=None):
-        super(SSLMiddleware, self).__init__(application, conf)
+    def __init__(self, application, *args, **kwargs):
+        super(SSLMiddleware, self).__init__(application, *args, **kwargs)
         self.oslo_conf.register_opts(OPTS, group='oslo_middleware')
 
     def process_request(self, req):

oslo_middleware/tests/test_base.py

@@ -14,28 +14,25 @@
 
 import webob
 
+from oslo_middleware.base import ConfigurableMiddleware
 from oslo_middleware.base import Middleware
 from oslotest.base import BaseTestCase
 
 
+@webob.dec.wsgify
+def application(req):
+    return 'Hello, World!!!'
+
+
 class TestBase(BaseTestCase):
     """Test the base middleware class."""
 
-    def setUp(self):
-        """Setup the tests."""
-        super(BaseTestCase, self).setUp()
-
     def test_extend_with_request(self):
         """Assert that a newer middleware behaves as appropriate.
 
         This tests makes sure that the request is passed to the
         middleware's implementation.
         """
-        # Create an application.
-        @webob.dec.wsgify
-        def application(req):
-            return 'Hello, World!!!'
-
         # Bootstrap the application
         self.application = RequestBase(application)
 
@@ -52,11 +49,6 @@ class TestBase(BaseTestCase):
         middleware's implementation, and that there are no other expected
         errors.
         """
-        # Create an application.
-        @webob.dec.wsgify
-        def application(req):
-            return 'Hello, World!!!'
-
         # Bootstrap the application
         self.application = NoRequestBase(application)
 
@@ -66,6 +58,16 @@ class TestBase(BaseTestCase):
 
         self.assertTrue(self.application.called_without_request)
 
+    def test_paste_deploy_legacy(self):
+        app = LegacyMiddlewareTest.factory(
+            {'global': True}, local=True)(application)
+        self.assertEqual(app.conf, {})
+
+    def test_paste_deploy_configurable(self):
+        app = ConfigurableMiddlewareTest.factory(
+            {'global': True}, local=True)(application)
+        self.assertEqual(app.conf, {'global': True, 'local': True})
+
 
 class NoRequestBase(Middleware):
     """Test middleware, implements old model."""
@@ -79,3 +81,11 @@ class RequestBase(Middleware):
     def process_response(self, response, request):
         self.called_with_request = True
         return response
+
+
+class ConfigurableMiddlewareTest(ConfigurableMiddleware):
+    pass
+
+
+class LegacyMiddlewareTest(Middleware):
+    pass