PoC: add proxy support

Proof of concept implementation of the proxy support described in #39.
It uses wsgiprox and re-uses werkzeug's own wsgi server, and it works like charm.

Currently implemented in a separate class.
See test_proxy.py for example.

Two minor things:
- wsgiprox uses gevent, yay
- creates a 'ca' directory in cwd

pytest_httpserver/__init__.py

@@ -5,7 +5,7 @@
 
 # flake8: noqa
 
-from .httpserver import HTTPServer
+from .httpserver import HTTPServer, HTTPProxy
 from .httpserver import HTTPServerError, Error, NoHandlerError
 from .httpserver import WaitingSettings, HeaderValueMatcher, RequestHandler
 from .httpserver import URIPattern, URI_DEFAULT, METHOD_ALL

pytest_httpserver/httpserver.py

@@ -19,6 +19,8 @@
 
 import werkzeug.urls
 from werkzeug.datastructures import MultiDict
+from wsgiprox.wsgiprox import WSGIProxMiddleware
+
 
 URI_DEFAULT = ""
 METHOD_ALL = "__ALL"
@@ -1118,3 +1120,12 @@ def __exit__(self, *args, **kwargs):
         """
         if self.is_running():
             self.stop()
+
+
+class HTTPProxy(HTTPServer):
+    def start(self):
+        proxy = WSGIProxMiddleware(self.application, "/proxy/", "wsgiprox")
+        self.server = make_server(self.host, self.port, proxy, ssl_context=self.ssl_context)
+        self.port = self.server.port  # Update port (needed if `port` was set to 0)
+        self.server_thread = threading.Thread(target=self.thread_target)
+        self.server_thread.start()

setup.py

@@ -19,6 +19,7 @@
     python_requires=">=3.4",
     install_requires=[
         "typing;python_version<'3.5'",
+        "wsgiprox",
         "werkzeug"
     ],
     extras_require={

tests/test_proxy.py

@@ -0,0 +1,16 @@
+
+import requests
+from pytest_httpserver import HTTPProxy
+
+
+def test_proxy():
+    proxy = HTTPProxy(port=8080)
+    proxy.expect_request("/proxy/http://example.com/path/file.html").respond_with_data("Hello world!")
+
+    proxy.start()
+    try:
+        resp = requests.get("http://example.com/path/file.html", proxies={"http": "http://localhost:8080/"})
+        assert resp.status_code == 200
+        assert resp.text == "Hello world!"
+    finally:
+        proxy.stop()