Initially, this project was created for myself, I needed to implement identification, authentication and authorization. In the future, there was a need to limit requests for each user on every endpoint, create API plans. There were a lot of microservices and to keep in each microservice the logic for limiting endpoints, security logic, logging etc. - meaningless. Therefore, all this functionality is located at a single entry point, which already implements all the necessary tasks with security, limiting, etc., while microservices now directly solve their tasks.

pip install fastapi_gateway

1.5k - 3k RPC.

gitshit@git ~ % wrk -t 4 -c 40 http://gateway.localtest.me:8003/gateway_endpoint/path_param/12
Running 10s test @ http://gateway.localtest.me:8003/gateway_endpoint/path_param/12
  4 threads and 40 connections
  Thread Stats   Avg      Stdev     Max   +/- Stdev
    Latency    30.11ms   33.65ms 312.55ms   95.98%
    Req/Sec   395.03    218.80     0.89k    73.21%
  15550 requests in 10.05s, 2.31MB read
Requests/sec:   1547.81
Transfer/sec:    235.81KB

from starlette import status
from starlette.requests import Request
from starlette.responses import Response
from fastapi_gateway import route
from fastapi import FastAPI
from pydantic import BaseModel
from fastapi import Depends
from fastapi.security import APIKeyHeader
from starlette import status
from starlette.exceptions import HTTPException

app = FastAPI(title='API Gateway')
SERVICE_URL = "http://microservice.localtest.me:8002"

API_KEY_NAME = "x-api-key"

api_key_header = APIKeyHeader(
    name=API_KEY_NAME,
    auto_error=False
)


def check_api_key(key: str = Depends(api_key_header)):
    if key:
        return key
    raise HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="You didn't pass the api key in the header! Header: x-api-key",
    )


class FooModel(BaseModel):
    example_int: int
    example_str: str


@route(
    request_method=app.post,
    service_url=SERVICE_URL,
    gateway_path='/query_and_body_path/{path}',
    service_path='/v1/query_and_body_path/{path}',
    query_params=['query_int', 'query_str'],
    body_params=['test_body'],
    status_code=status.HTTP_200_OK,
    tags=['Query', 'Body', 'Path'],
    dependencies=[
        Depends(check_api_key)
    ],
)
async def check_query_params_and_body(
        path: int, query_int: int, query_str: str,
        test_body: FooModel, request: Request, response: Response
):
    pass

• request_method - is a callable (like app.get, app.post, foo_router.patch and so on.).
• service_url - the path to the endpoint on another service (like "https://microservice1.example.com").
• service_path - the path to the method in microservice (like "/v1/microservice/users").
• gateway_path - is the path to bind gateway.
  For example, your gateway api is located here - https://gateway.example.com and the path to endpoint (gateway_path) - "/users" then the full way to this method will be - https://gateway.example.com/users
• override_headers - Boolean value allows you to return all the headlines that were created by microservice in gateway.
• query_params - used to extract query parameters from endpoint and transmission to microservice
• form_params - used to extract form model parameters from endpoint and transmission to microservice
• param body_params - used to extract body model from endpoint and transmission to microservice

⚠️ - Be sure to transfer the name of the argument to the router, which is in the endpoint func!

query_params - List[Query]
body_params - List[Body]
form_params - List[File, Form]

In more detail how to transmit body, form and query (photo)