Add X-Original-URI support

.gitignore

@@ -11,3 +11,6 @@ htmlcov/
 *.swp
 .tox/
 .idea/
+venv
+.vscode
+src

connexion/apis/abstract.py

@@ -1,4 +1,5 @@
 import abc
+import copy
 import logging
 import pathlib
 import sys
@@ -79,7 +80,9 @@ def __init__(self, specification, base_path=None, arguments=None,
         logger.debug('Options Loaded',
                      extra={'swagger_ui': self.options.openapi_console_ui_available,
                             'swagger_path': self.options.openapi_console_ui_from_dir,
-                            'swagger_url': self.options.openapi_console_ui_path})
+                            'swagger_url': self.options.openapi_console_ui_path,
+                            'proxy_uri_prefix_header': self.options.proxy_uri_prefix_header
+                            })
 
         self._set_base_path(base_path)
 
@@ -113,7 +116,7 @@ def __init__(self, specification, base_path=None, arguments=None,
                 self.specification.security_definitions
             )
 
-    def _set_base_path(self, base_path=None):
+    def _set_base_path(self, base_path):
         if base_path is not None:
             # update spec to include user-provided base_path
             self.specification.base_path = base_path
@@ -134,6 +137,19 @@ def add_swagger_ui(self):
         Adds swagger ui to {base_path}/ui/
         """
 
+    def _get_specs_behind_proxy(self, prefix_uri):
+        """
+        Update OpenAPI base path using specified original_uri. (from header set by the proxy).
+        :param prefix_uri: uri to use to prefix base_path
+        :return: Updated raw specifications
+        """
+
+        if not prefix_uri:
+            return self.specification.raw
+        specs = copy.copy(self.specification.raw)
+        self.specification.set_base_path(specs, prefix_uri + self.base_path)
+        return specs
+
     @abc.abstractmethod
     def add_auth_on_not_found(self, security, security_definitions):
         """

connexion/apis/aiohttp_api.py

@@ -79,10 +79,11 @@ def add_openapi_json(self):
 
     @asyncio.coroutine
     def _get_openapi_json(self, req):
+        specs = self._get_specs_behind_proxy(req.headers.get(self.options.proxy_uri_prefix_header))
         return web.Response(
             status=200,
             content_type='application/json',
-            body=self.jsonifier.dumps(self.specification.raw)
+            body=self.jsonifier.dumps(specs)
         )
 
     def add_swagger_ui(self):
@@ -114,7 +115,8 @@ def add_swagger_ui(self):
     @aiohttp_jinja2.template('index.j2')
     @asyncio.coroutine
     def _get_swagger_ui_home(self, req):
-        return {'openapi_spec_url': (self.base_path +
+        base_path = req.headers.get(self.options.proxy_uri_prefix_header, '') + self.base_path
+        return {'openapi_spec_url': (base_path +
                                      self.options.openapi_spec_path)}
 
     def add_auth_on_not_found(self, security, security_definitions):

connexion/apis/flask_api.py

@@ -37,7 +37,12 @@ def add_openapi_json(self):
         endpoint_name = "{name}_openapi_json".format(name=self.blueprint.name)
         self.blueprint.add_url_rule(self.options.openapi_spec_path,
                                     endpoint_name,
-                                    lambda: flask.jsonify(self.specification.raw))
+                                    lambda: flask.jsonify(
+                                        self._get_specs_behind_proxy(
+                                            flask.request.headers.get(self.options.proxy_uri_prefix_header)
+                                            )
+                                        )
+                                    )
 
     def add_swagger_ui(self):
         """
@@ -278,9 +283,10 @@ def console_ui_home(self):
 
         :return:
         """
+        base_path = flask.request.headers.get(self.options.proxy_uri_prefix_header, '') + self.base_path
         return flask.render_template(
             'index.j2',
-            openapi_spec_url=(self.base_path + self.options.openapi_spec_path)
+            openapi_spec_url=(base_path + self.options.openapi_spec_path)
         )
 
     def console_ui_static_files(self, filename):

connexion/options.py

@@ -120,6 +120,16 @@ def uri_parser_class(self):
         """
         return self._options.get('uri_parser_class', None)
 
+    @property
+    def proxy_uri_prefix_header(self):
+        # type: () -> str
+        """
+        The header to use to dynamically prefix specification base_path.
+        This is header need to be set by reverse proxy when there is a rewrite rule.
+        Default: ''
+        """
+        return self._options.get('proxy_uri_prefix_header', '')
+
 
 def filter_values(dictionary):
     # type: (dict) -> dict

connexion/spec.py

@@ -69,6 +69,25 @@ def version(self):
     def security(self):
         return self._spec.get('security')
 
+    @property
+    def base_path(self):
+        return self._get_base_path()
+
+    @base_path.setter
+    def base_path(self, base_path):
+        base_path = canonical_base_path(base_path)
+        self.set_base_path(self._raw_spec, base_path)
+        self.set_base_path(self._spec, base_path)
+
+    @abc.abstractmethod
+    def _get_base_path(self):
+        """ Return base path from specs """
+
+    @staticmethod
+    @abc.abstractmethod
+    def set_base_path(specs, base_path):
+        """ Set base path adapted to specification format """
+
     def __getitem__(self, k):
         return self._spec[k]
 
@@ -188,15 +207,12 @@ def response_definitions(self):
     def security_definitions(self):
         return self._spec.get('securityDefinitions', {})
 
-    @property
-    def base_path(self):
+    def _get_base_path(self):
         return canonical_base_path(self._spec.get('basePath', ''))
 
-    @base_path.setter
-    def base_path(self, base_path):
-        base_path = canonical_base_path(base_path)
-        self._raw_spec['basePath'] = base_path
-        self._spec['basePath'] = base_path
+    @staticmethod
+    def set_base_path(specs, base_path):
+        specs['basePath'] = base_path
 
     @classmethod
     def _validate_spec(cls, spec):
@@ -231,8 +247,7 @@ def _validate_spec(cls, spec):
         except OpenAPIValidationError as e:
             raise InvalidSpecification.create_from(e)
 
-    @property
-    def base_path(self):
+    def _get_base_path(self):
         servers = self._spec.get('servers', [])
         try:
             # assume we're the first server in list
@@ -247,9 +262,6 @@ def base_path(self):
             base_path = ''
         return canonical_base_path(base_path)
 
-    @base_path.setter
-    def base_path(self, base_path):
-        base_path = canonical_base_path(base_path)
-        user_servers = [{'url': base_path}]
-        self._raw_spec['servers'] = user_servers
-        self._spec['servers'] = user_servers
+    @staticmethod
+    def set_base_path(specs, base_path):
+        specs['servers'] = [{'url': base_path}]

examples/openapi3/external_reverse_proxy/README.rst

@@ -0,0 +1,39 @@
+=====================
+External Reverse Proxy Example
+=====================
+
+This example demonstrates how to run a connexion application behind an external reverse proxy with rewrite rule.
+
+Setup NGINX reverse proxy:
+
+.. code-block:: NGINX
+
+    server {
+      listen 9000;
+      listen [::]:9000;
+
+      server_name example.com;
+
+      location /reverse_proxied/ {
+        # Define the location of the proxy server to send the request to
+        proxy_pass http://localhost:8080/;
+        # Add prefix header
+        proxy_set_header X-Forwarded-Prefix $scheme://$host:$server_port/reverse_proxied;
+      }
+    }
+
+
+And start application:
+
+.. code-block:: bash
+
+    $ sudo pip3 install --upgrade connexion[swagger-ui]  # install Connexion from PyPI
+    $ ./app.py
+
+Swagger UI can be accessed with direct connexion:
+
+    http://localhost:8080/v1/ui
+
+And through NGINX proxy with rewrite rule:
+
+    http://localhost:9000/reverse_proxied/v1/ui

examples/openapi3/external_reverse_proxy/app.py

@@ -0,0 +1,14 @@
+#!/usr/bin/env python3
+
+import connexion
+
+
+def hello():
+    return "hello"
+
+
+if __name__ == '__main__':
+    app = connexion.FlaskApp(__name__, options={'proxy_uri_prefix_header': 'X-Forwarded-Prefix'})
+    app.add_api('openapi/openapi.yaml')
+    app.run(port=8080)
+

examples/openapi3/external_reverse_proxy/openapi/openapi.yaml

@@ -0,0 +1,18 @@
+openapi: 3.0.0
+info:
+  title: Path-Altering Reverse Proxy Example
+  version: '1.0'
+servers:
+- url: http://localhost:8080/v1
+paths:
+  /hello:
+    get:
+      summary: say hi
+      operationId: app.hello
+      responses:
+        '200':
+          description: hello
+          content:
+            text/plain:
+              schema:
+                type: string

tests/aiohttp/test_aiohttp_simple_api.py

@@ -88,10 +88,6 @@ def test_swagger_ui(aiohttp_api_spec_dir, aiohttp_client):
     assert swagger_ui.status == 200
     assert b'url = "/v1.0/swagger.json"' in (yield from swagger_ui.read())
 
-    swagger_ui = yield from app_client.get('/v1.0/ui/')
-    assert swagger_ui.status == 200
-    assert b'url = "/v1.0/swagger.json"' in (yield from swagger_ui.read())
-
 
 @asyncio.coroutine
 def test_swagger_ui_index(aiohttp_api_spec_dir, aiohttp_client):
@@ -144,6 +140,60 @@ def test_no_swagger_ui(aiohttp_api_spec_dir, aiohttp_client):
     assert swagger_ui2.status == 404
 
 
+@asyncio.coroutine
+def test_swagger_json_behind_proxy(simple_api_spec_dir, aiohttp_client):
+    """ Verify the swagger.json file is returned with base_path updated according to X-Original-URI header. """
+    app = AioHttpApp(__name__, port=5001,
+                     specification_dir=simple_api_spec_dir,
+                     options={'proxy_uri_prefix_header': 'X-Forwarded-Prefix'},
+                     debug=True)
+    api = app.add_api('swagger.yaml')
+
+    app_client = yield from aiohttp_client(app.app)
+    headers = {'X-Forwarded-Prefix': '/behind/proxy'}
+
+    swagger_ui = yield from app_client.get('/v1.0/ui/', headers=headers)
+    assert swagger_ui.status == 200
+    assert b'url = "/behind/proxy/v1.0/swagger.json"' in (yield from swagger_ui.read())
+
+    swagger_json = yield from app_client.get('/v1.0/swagger.json', headers=headers)
+    assert swagger_json.status == 200
+    assert swagger_json.headers.get('Content-Type') == 'application/json'
+    json_ = yield from swagger_json.json()
+
+    assert api.specification.raw['basePath'] == '/v1.0', "Original specifications should not have been changed"
+    assert json_.get('basePath') == '/behind/proxy/v1.0', "basePath should contains original URI"
+    json_['basePath'] = api.specification.raw['basePath']
+    assert api.specification.raw == json_, "Only basePath should have been updated"
+
+
+@asyncio.coroutine
+def test_openapi_json_behind_proxy(simple_api_spec_dir, aiohttp_client):
+    """ Verify the swagger.json file is returned with base_path updated according to X-Original-URI header. """
+    app = AioHttpApp(__name__, port=5001,
+                     specification_dir=simple_api_spec_dir,
+                     options={'proxy_uri_prefix_header': 'My-URI-Header'},
+                     debug=True)
+    api = app.add_api('openapi.yaml')
+
+    app_client = yield from aiohttp_client(app.app)
+    headers = {'My-URI-Header': '/behind/proxy'}
+
+    swagger_ui = yield from app_client.get('/v1.0/ui/', headers=headers)
+    assert swagger_ui.status == 200
+    assert b'url: "/behind/proxy/v1.0/openapi.json"' in (yield from swagger_ui.read())
+
+    swagger_json = yield from app_client.get('/v1.0/openapi.json', headers=headers)
+    assert swagger_json.status == 200
+    assert swagger_json.headers.get('Content-Type') == 'application/json'
+    json_ = yield from swagger_json.json()
+
+    assert json_.get('servers', [{}])[0].get('url') == '/behind/proxy/v1.0', "basePath should contains original URI"
+    assert api.specification.raw.get('servers', [{}])[0].get('url') != '/behind/proxy/v1.0', "Original specifications should not have been changed"
+    json_['servers'] = api.specification.raw.get('servers')
+    assert api.specification.raw == json_, "Only basePath should have been updated"
+
+
 @asyncio.coroutine
 def test_middlewares(aiohttp_api_spec_dir, aiohttp_client):
     @asyncio.coroutine

tests/api/test_responses.py

@@ -43,6 +43,27 @@ def test_app(simple_app):
     assert greeting_response['greeting'] == 'Hello jsantos'
 
 
+def test_openapi_json_behind_proxy(simple_app):
+    """ Verify the swagger.json file is returned with base_path updated according to X-Original-URI header. """
+    app_client = simple_app.app.test_client()
+    headers = {'X-Forwarded-Prefix': '/behind/proxy'}
+
+    swagger_ui = app_client.get('/v1.0/ui/', headers=headers)
+    assert swagger_ui.status_code == 200
+
+    swagger_json = app_client.get('/v1.0/' + simple_app._spec_file.replace('.yaml', '.json'), headers=headers)
+    assert swagger_json.status_code == 200
+    assert swagger_json.headers.get('Content-Type') == 'application/json'
+    json_ = json.loads(swagger_json.data.decode('utf-8'))
+
+    if simple_app._spec_file == 'openapi.yaml':
+        assert b'url: "/behind/proxy/v1.0/openapi.json"' in swagger_ui.data
+        assert json_.get('servers', [{}])[0].get('url') == '/behind/proxy/v1.0', "basePath should contains original URI"
+    else:
+        assert b'url = "/behind/proxy/v1.0/swagger.json"' in swagger_ui.data
+        assert json_.get('basePath') == '/behind/proxy/v1.0', "basePath should contains original URI"
+
+
 def test_produce_decorator(simple_app):
     app_client = simple_app.app.test_client()
 
@@ -264,14 +285,15 @@ def test_get_unicode_response(simple_app):
     app_client = simple_app.app.test_client()
     resp = app_client.get('/v1.0/get_unicode_response')
     actualJson = {u'currency': u'\xa3', u'key': u'leena'}
-    assert json.loads(resp.data.decode('utf-8','replace')) == actualJson
+    assert json.loads(resp.data.decode('utf-8', 'replace')) == actualJson
 
 
 def test_get_enum_response(simple_app):
     app_client = simple_app.app.test_client()
     resp = app_client.get('/v1.0/get_enum_response')
     assert resp.status_code == 200
 
+
 def test_get_httpstatus_response(simple_app):
     app_client = simple_app.app.test_client()
     resp = app_client.get('/v1.0/get_httpstatus_response')

tests/conftest.py

@@ -103,6 +103,7 @@ def build_app_from_fixture(api_spec_folder, spec_file='openapi.yaml', **kwargs):
     cnx_app = App(__name__,
                   port=5001,
                   specification_dir=FIXTURES_FOLDER / api_spec_folder,
+                  options={'proxy_uri_prefix_header': 'X-Forwarded-Prefix'},
                   debug=debug)
 
     cnx_app.add_api(spec_file, **kwargs)