Neda/Back/core/rate_limit.py

50 lines
2.1 KiB
Python

# core/rate_limit.py
from fastapi import Request, HTTPException, status
from db.redis import redis_client
class RateLimiter:
def __init__(self, requests: int, window_seconds: int, scope: str = "global"):
"""
:param requests: number of requests allowed
:param window_seconds: window time in seconds
:param scope: type of limit ("global" for all site, "endpoint" for a specific path)
"""
self.requests = requests
self.window_seconds = window_seconds
self.scope = scope
async def __call__(self, request: Request):
# getting client ip
client_ip = request.client.host if request.client else "127.0.0.1"
# when project is in docker and behind nginx, the real ip is in the headers
real_ip = request.headers.get("x-real-ip", request.headers.get("x-forwarded-for", client_ip))
# if there are multiple ips, take the first ip (the real user ip)
real_ip = real_ip.split(",")[0].strip()
# creating redis key based on scope
if self.scope == "global":
# key for global limit (e.g., rate_limit:global:192.168.1.5)
key = f"rate_limit:global:{real_ip}"
else:
# key for endpoint limit (e.g., rate_limit:endpoint:192.168.1.5:/admin/login)
path = request.scope["path"]
key = f"rate_limit:endpoint:{real_ip}:{path}"
# adding 1 to the number of requests for this ip in redis
current_count = await redis_client.incr(key)
# if this is the first request in this time window, set the expiration time (TTL)
if current_count == 1:
await redis_client.expire(key, self.window_seconds)
# if the number of requests exceeds the limit, access is blocked
if current_count > self.requests:
# penalty: if someone spams, the time they are blocked is extended from zero again
await redis_client.expire(key, self.window_seconds)
raise HTTPException(
status_code=status.HTTP_429_TOO_MANY_REQUESTS,
detail="Too many requests. Please try again later."
)