adding kamo's routing magic

week5/app.py

@@ -12,7 +12,31 @@ def allowed_file(filename):
     return '.' in filename and \
            filename.rsplit('.', 1)[1].lower() in ALLOWED_EXTENSIONS
 
+# Kamo's prefix to add /soupboat/padliography to all the routes
+class PrefixMiddleware(object):
+    def __init__(self, app, prefix=""):
+        self.app = app
+        self.prefix = prefix
+
+    def __call__(self, environ, start_response):
+
+        if environ["PATH_INFO"].startswith(self.prefix):
+            environ["PATH_INFO"] = environ["PATH_INFO"][len(self.prefix):]
+            environ["SCRIPT_NAME"] = self.prefix
+            return self.app(environ, start_response)
+        else:
+            start_response("404", [("Content-Type", "text/plain")])
+            return ["This url does not belong to the app.".encode()]
+
+# create flask application
 app = Flask(__name__)
+
+# Get the URL prefix for the soupboat
+# register the middleware to use our base_url as prefix on all the requests
+base_url = os.environ.get('BASE_URL', '')
+app.wsgi_app = PrefixMiddleware(app.wsgi_app, prefix=base_url)
+
+# configure the upload folder
 app.config['UPLOAD_FOLDER'] = UPLOAD_FOLDER
 
 @app.route("/")