Added support for chunked encoded requests when running gunicorn. Fixed

#340.

In this commit:

- when we see a Transfer-Encoding: chunked request, and the server is gunicorn,
  we set environ wsgi.input_terminated, which is required by Werkzeug in the
  absence of Content-Lenght, or it will empty the data stream.
- for chunked requests to non-gunicorn, return 501 Not Implemented.

httpbin/core.py

@@ -15,7 +15,7 @@
 import uuid
 import argparse
 
-from flask import Flask, Response, request, render_template, redirect, jsonify as flask_jsonify, make_response, url_for
+from flask import Flask, Response, request, render_template, redirect, jsonify as flask_jsonify, make_response, url_for, abort
 from flask_common import Common
 from six.moves import range as xrange
 from werkzeug.datastructures import WWWAuthenticate, MultiDict
@@ -84,6 +84,30 @@ def jsonify(*args, **kwargs):
 # -----------
 # Middlewares
 # -----------
+"""
+https://github.com/kennethreitz/httpbin/issues/340
+Adds a middleware to provide chunked request encoding support running under
+gunicorn only.
+Werkzeug required environ 'wsgi.input_terminated' to be set otherwise it
+empties the input request stream.
+- gunicorn seems to support input_terminated but does not add the environ,
+  so we add it here.
+- flask will hang and does not seem to properly terminate the request, so
+  we explicityly deny chunked requests.
+"""
+@app.before_request
+def before_request():
+    if request.environ.get('HTTP_TRANSFER_ENCODING', '').lower() == 'chunked':
+        server = request.environ.get('SERVER_SOFTWARE', '')
+        if server.lower().startswith('gunicorn/'):
+            if 'wsgi.input_terminated' in request.environ:
+                app.logger.warning("environ wsgi.input_terminated already set, keeping: %s"
+                                   % request.environ['wsgi.input_terminated'])
+            else:
+                request.environ['wsgi.input_terminated'] = 1
+        else:
+            abort(501, "Chunked requests are not supported for server %s" % server)
+
 @app.after_request
 def set_cors_headers(response):
     response.headers['Access-Control-Allow-Origin'] = request.headers.get('Origin', '*')

test_httpbin.py

@@ -206,6 +206,25 @@ def test_post_file_with_missing_content_type_header(self):
         )
         self.assertEqual(response.status_code, 200)
 
+    """
+    This is currently a sort of negative-test.
+    We validate that when running Flask-only server that
+    Transfer-Encoding: chunked requests are unsupported and
+    we return 501 Not Implemented
+    """
+    def test_post_chunked(self):
+        data = '{"animal":"dog"}'
+        response = self.app.post(
+            '/post',
+            content_type='application/json',
+            headers=[('Transfer-Encoding', 'chunked')],
+            data=data,
+        )
+        self.assertEqual(response.status_code, 501)
+        #self.assertEqual(response.status_code, 200)
+        #self.assertEqual(json.loads(response.data.decode('utf-8'))['data'], '{"animal":"dog"}')
+        #self.assertEqual(json.loads(response.data.decode('utf-8'))['json'], {"animal": "dog"})
+
     def test_set_cors_headers_after_request(self):
         response = self.app.get('/get')
         self.assertEqual(