Add Middleware to Handle Duplicate Slashes in URLs (microsoft#51)

This PR adds some FastAPI middleware to fix URLs that have duplicate forward slashes. For example, if the user puts the following in their .env file.... ```dotenv TEST_OPENAI_ENDPOINT=http://localhost:8000/ ``` ... then the tests will generate urls such as `http://localhost:8000//openai/foo/bar/baz`. Notice the double forward slash. This causes the simulator to generate errors. This is an easy config mistake to make, so this middleware helps address this problem by removing these duplicates.
mluker · Sep 16, 2024 · 9937f25 · 9937f25
2 parents da8704e + a0f0d76
commit 9937f25
Showing 1 changed file with 14 additions and 2 deletions.
diff --git a/src/aoai-api-simulator/src/aoai_api_simulator/app_builder.py b/src/aoai-api-simulator/src/aoai_api_simulator/app_builder.py
@@ -1,7 +1,7 @@
 import logging
+import re
 import traceback
 from typing import Annotated
-from fastapi import Depends, FastAPI, Request, Response, HTTPException
 
 from aoai_api_simulator.auth import validate_api_key_header
 from aoai_api_simulator.config_loader import get_config, set_config
@@ -11,12 +11,13 @@
 from aoai_api_simulator.models import RequestContext
 from aoai_api_simulator.record_replay.handler import RecordReplayHandler
 from aoai_api_simulator.record_replay.persistence import YamlRecordingPersister
-
+from fastapi import Depends, FastAPI, HTTPException, Request, Response
 
 logger = logging.getLogger(__name__)
 
 app = FastAPI()
 
+repeated_quotes = re.compile(r"//+")
 
 # pylint: disable-next=invalid-name
 record_replay_handler = None
@@ -53,6 +54,17 @@ def _default_validate_api_key_header(request: Request):
     validate_api_key_header(request=request, header_name="api-key", allowed_key_value=get_config().simulator_api_key)
 
 
+# This middleware replaces double slashes in paths with a single slash
+@app.middleware("http")
+async def fix_double_slash_urls(request: Request, call_next):
+    if repeated_quotes.search(request.url.path):
+        new_url = request.url.replace(path=repeated_quotes.sub("/", request.url.path))
+        request.scope["path"] = new_url.path
+
+    response = await call_next(request)
+    return response
+
+
 @app.get("/")
 async def root():
     return {"message": "👋 aoai-api-simulator is running"}