Add aioredis for storing already decoded ticket contracts

Signed-off-by: David Sn <[email protected]>

main.py

@@ -1,10 +1,12 @@
 import base64
+import os
 import time
 
 from datetime import datetime, timedelta
 from io import BytesIO
 
 import aiohttp
+import aioredis
 import zxingcpp
 
 from fastapi import FastAPI, Header, Request
@@ -16,6 +18,9 @@
 # Ticket contract endpoint
 CONTRACT_URL = "https://api.kkm.krakow.pl/api/v1/mkkm/tickets/{ticket_guid}/contract"
 
+# Redis settings
+REDIS_URL = os.getenv("REDIS_URL", "redis://user:sEcRet@localhost/")
+
 
 class HTTPException(Exception):
     def __init__(self, status_code: int, message: str):
@@ -42,6 +47,13 @@ class ErrorResponse(BaseModel):
     redoc_url=None
 )
 
+redis = aioredis.from_url(REDIS_URL, decode_responses=True)
+
+
+@app.on_event("shutdown")
+async def shutdown_event():
+    await redis.close()
+
 
 @app.middleware("http")
 async def add_process_time_header(request: Request, call_next):
@@ -68,6 +80,9 @@ async def http_exception_handler(request: Request, exception: HTTPException):
 })
 async def get_contract(ticket_guid: str, authorization: str = Header(Required)):
     """Returns decoded AZTEC barcode data"""
+    if await redis.exists(f"ticket:{ticket_guid}:contract"):
+        return {"aztec": await redis.get(f"ticket:{ticket_guid}:contract")}
+
     auth_headers = {
         "User-Agent": "mobileKKM/contract_proxy",
         "Authorization": authorization
@@ -87,4 +102,6 @@ async def get_contract(ticket_guid: str, authorization: str = Header(Required)):
                 raise HTTPException(status_code=500, message="Could not decode barcode from image.") from exc
 
             expires = datetime.utcnow().replace(second=0, microsecond=0) + timedelta(minutes=2)
+
+            await redis.set(f"ticket:{ticket_guid}:contract", result.text, ex=(expires - datetime.utcnow()).seconds)
             return {"aztec": result.text, "expires": expires}

requirements.txt

@@ -1,5 +1,7 @@
 aiohttp
+aioredis
 fastapi
 pillow
+pydantic
 uvicorn
 zxing-cpp