Make all CallbackResponse requests into a Werkzeug Request

The "request" object in CallbackResponse is the PreparedRequest send by
whatever client is used to contact the mocked moto service. This can end
up with unparsed bodies, as we added for processing presigned post
requests in #2155. This will make sure that all of the requests comming
in from mocked functions also get processed by werkzeug as if it was
running a live server.

moto/core/models.py

@@ -12,6 +12,8 @@ from io import BytesIO
 from collections import defaultdict
 from botocore.handlers import BUILTIN_HANDLERS
 from botocore.awsrequest import AWSResponse
+from six.moves.urllib.parse import urlparse
+from werkzeug.wrappers import Request
 
 import mock
 from moto import settings
@@ -175,6 +177,24 @@ class CallbackResponse(responses.CallbackResponse):
         """
         Need to override this so we can pass decode_content=False
         """
+        if not isinstance(request, Request):
+            url = urlparse(request.url)
+            if request.body is None:
+                body = None
+            elif isinstance(request.body, six.text_type):
+                body = six.BytesIO(six.b(request.body))
+            else:
+                body = six.BytesIO(request.body)
+            req = Request.from_values(
+                path='?'.join([url.path, url.query]),
+                input_stream=body,
+                content_length=request.headers.get("Content-Length"),
+                content_type=request.headers.get("Content-Type"),
+                method=request.method,
+                base_url='{scheme}://{netloc}'.format(scheme=url.scheme, netloc=url.netloc),
+                headers=[(k, v) for k, v in six.iteritems(request.headers)]
+            )
+            request = req
         headers = self.get_headers()
 
         result = self.callback(request)

moto/s3/responses.py

@@ -5,7 +5,6 @@ import sys
 
 import six
 from botocore.awsrequest import AWSPreparedRequest
-from werkzeug.wrappers import Request
 
 from moto.core.utils import str_to_rfc_1123_datetime, py2_strip_unicode_keys
 from six.moves.urllib.parse import parse_qs, urlparse, unquote, parse_qsl
@@ -797,14 +796,6 @@ class ResponseObject(_TemplateEnvironmentMixin, ActionAuthenticatorMixin):
         if hasattr(request, "form"):
             # Not HTTPretty
             form = request.form
-        elif request.headers.get("Content-Type").startswith("multipart/form-data"):
-            request = Request.from_values(
-                input_stream=six.BytesIO(request.body),
-                content_length=request.headers["Content-Length"],
-                content_type=request.headers["Content-Type"],
-                method="POST",
-            )
-            form = request.form
         else:
             # HTTPretty, build new form object
             body = body.decode()