modify spec base_path on request

connexion/apis/flask_api.py

@@ -10,6 +10,7 @@
 from connexion.decorators.produces import NoContent
 from connexion.handlers import AuthErrorHandler
 from connexion.lifecycle import ConnexionRequest, ConnexionResponse
+from connexion.spec import Specification
 from connexion.utils import Jsonifier, is_json_mimetype
 
 logger = logging.getLogger('connexion.apis.flask_api')
@@ -35,10 +36,18 @@ def add_openapi_json(self):
         logger.debug('Adding spec json: %s/%s', self.base_path,
                      self.options.openapi_spec_path)
         endpoint_name = "{name}_openapi_json".format(name=self.blueprint.name)
-        print("endpoint name", endpoint_name)
+
+        def spec_for_url():
+            """ Modify base_path in the spec based on incoming url
+                This fixes problems with reverse proxies changing the path.
+            """
+            openapi_json_route = ".".join([self.blueprint.name, endpoint_name])
+            base_path = flask.url_for(openapi_json_route)
+            return flask.jsonify(self.specification.with_base_path(base_path).raw)
+
         self.blueprint.add_url_rule(self.options.openapi_spec_path,
                                     endpoint_name,
-                                    lambda: flask.jsonify(self.specification.raw))
+                                    spec_for_url)
 
     def add_swagger_ui(self):
         """

connexion/spec.py

@@ -151,6 +151,12 @@ def load(cls, spec, arguments=None):
             return cls.from_file(spec, arguments=arguments)
         return cls.from_dict(spec)
 
+    def with_base_path(self, base_path):
+        # FIXME creating a whole new spec is slow
+        new_spec = Specification.from_dict(self.raw)
+        new_spec.base_path = base_path
+        return new_spec
+
 
 class Swagger2Specification(Specification):
     yaml_name = 'swagger.yaml'