Merge pull request #352 from jessepollak/add-wsgi-flexibility-to-server

Add wsgi flexibility to server

CHANGES

@@ -10,6 +10,8 @@ Version 2.4.1
 
 Released PENDING
 
+* Enhanced :class: `~nameko.web.server.WebServer` with ``get_wsgi_app`` and ``get_wsgi_server``
+to allow easy usage of WSGI middleware and modifications of the WSGI server.
 * Enhanced :func:`~nameko.testing.services.replace_dependencies` to allow
   specific replacement values to be provided with named arguments.
 

CONTRIBUTORS.txt

@@ -23,3 +23,4 @@ Jakub Borys (@kooba)
 Andriy Kogut (@andriykohut)
 Fabrizio Romano (@gianchub)
 Alexandre Héaumé (@aheaume)
+Jesse Pollak (@jessepollak)

docs/contributing.rst

@@ -23,3 +23,10 @@ Pull requests are automatically built with `Travis-CI <https://travis-ci.org/one
     * Documentation builds successfully (including spell-check)
 
 See :ref:`getting in touch <getting_in_touch>` for more guidance on contributing.
+
+Running the tests
+--------------------
+
+There is a Makefile with convenience commands for running the tests. To run them locally you must have RabbitMQ :ref:`installed <installation>` and running, then call::
+
+    $ make test

docs/spelling_wordlist.txt

@@ -61,6 +61,7 @@ lifealike
 lifecycle
 localhost
 logstash
+makefile
 maximize
 memcached
 microservice

nameko/web/server.py

@@ -50,13 +50,18 @@ def finish(self):
 
 
 class WebServer(ProviderCollector, SharedExtension):
+    """A SharedExtension that wraps a WSGI interface for processing HTTP
+    requests.
+
+    WebServer can be subclassed to add additional WSGI functionality through
+    overriding the get_wsgi_server and get_wsgi_app methods.
+    """
 
     def __init__(self):
         super(WebServer, self).__init__()
         self._gt = None
         self._sock = None
         self._serv = None
-        self._wsgi_app = None
         self._starting = False
         self._is_accepting = True
 
@@ -77,15 +82,30 @@ def run(self):
     def start(self):
         if not self._starting:
             self._starting = True
-            self._wsgi_app = WsgiApp(self)
             self._sock = eventlet.listen(self.bind_addr)
-            self._serv = wsgi.Server(self._sock,
-                                     self._sock.getsockname(),
-                                     self._wsgi_app,
-                                     protocol=HttpOnlyProtocol,
-                                     debug=False)
+            self._serv = self.get_wsgi_server(self._sock, self.get_wsgi_app())
             self._gt = self.container.spawn_managed_thread(self.run)
 
+    def get_wsgi_app(self):
+        """Get the WSGI application used to process requests.
+
+        This method can be overriden to apply WSGI middleware or replace
+        the WSGI application all together.
+        """
+        return WsgiApp(self)
+
+    def get_wsgi_server(
+        self, sock, wsgi_app, protocol=HttpOnlyProtocol, debug=False
+    ):
+        """Get the WSGI server used to process requests."""
+        return wsgi.Server(
+            sock,
+            sock.getsockname(),
+            wsgi_app,
+            protocol=protocol,
+            debug=debug
+        )
+
     def stop(self):
         self._is_accepting = False
         self._gt.kill()

test/web/test_server.py

@@ -1,10 +1,17 @@
 from mock import patch
 import pytest
 import socket
+from eventlet import wsgi
+from werkzeug.contrib.fixers import ProxyFix
 
 from nameko.exceptions import ConfigurationError
-from nameko.web.handlers import http
-from nameko.web.server import BaseHTTPServer, parse_address
+from nameko.web.handlers import http, HttpRequestHandler
+from nameko.web.server import (
+    BaseHTTPServer,
+    parse_address,
+    WebServer,
+    HttpOnlyProtocol
+)
 
 
 class ExampleService(object):
@@ -21,7 +28,8 @@ def do_large(self, request):
 
 
 def test_broken_pipe(
-        container_factory, web_config, web_config_port,  web_session):
+    container_factory, web_config, web_config_port, web_session
+):
     container = container_factory(ExampleService, web_config)
     container.start()
 
@@ -36,7 +44,8 @@ def test_broken_pipe(
 
 
 def test_other_error(
-        container_factory, web_config, web_config_port, web_session):
+    container_factory, web_config, web_config_port, web_session
+):
     container = container_factory(ExampleService, web_config)
     container.start()
 
@@ -69,3 +78,69 @@ def test_parse_address(source, result):
 
     else:
         assert parse_address(source) == result
+
+
+def test_adding_middleware_with_get_wsgi_app(container_factory, web_config):
+
+    class CustomWebServer(WebServer):
+        def get_wsgi_app(self):
+            # get the original WSGI app that processes http requests
+            app = super(CustomWebServer, self).get_wsgi_app()
+            # apply the ProxyFix middleware as an example
+            return ProxyFix(app, num_proxies=1)
+
+    class CustomHttpRequestHandler(HttpRequestHandler):
+        server = CustomWebServer()
+
+    http = CustomHttpRequestHandler.decorator
+
+    class CustomServerExampleService(object):
+        name = 'customserverservice'
+
+        @http('GET', '/')
+        def do_index(self, request):
+            return ''
+
+    container = container_factory(CustomServerExampleService, web_config)
+    with patch.object(CustomWebServer, 'get_wsgi_server') as get_wsgi_server:
+        container.start()
+
+    wsgi_app = get_wsgi_server.call_args[0][1]
+    assert isinstance(wsgi_app, ProxyFix)
+
+
+def test_custom_wsgi_server_is_used(
+    container_factory, web_config, web_config_port, web_session
+):
+    def custom_wsgi_app(environ, start_response):
+        start_response('200 OK', [])
+        return 'Override'
+
+    class CustomWebServer(WebServer):
+        def get_wsgi_server(
+            self, sock, wsgi_app, protocol=HttpOnlyProtocol, debug=False
+        ):
+            return wsgi.Server(
+                sock,
+                sock.getsockname(),
+                custom_wsgi_app,
+                protocol=protocol,
+                debug=debug
+            )
+
+    class CustomHttpRequestHandler(HttpRequestHandler):
+        server = CustomWebServer()
+
+    http = CustomHttpRequestHandler.decorator
+
+    class CustomServerExampleService(object):
+        name = 'customserverservice'
+
+        @http('GET', '/')
+        def do_index(self, request):
+            return ''
+
+    container = container_factory(CustomServerExampleService, web_config)
+    container.start()
+
+    assert web_session.get('/').text == 'Override'