Aiohttp: execute subrequest inside current request

aiohttp-subrequest.py

import json

from aiohttp.web import Request, json_response


async def sub_request_handler(request: Request):
    request._read_bytes = None # to have an ability to clone the root request
    sub_requests = [
        {"url": "/api/v1/sub-url-1", "method": "POST", "payload": {"param1": "value1"}},
        {"url": "/api/v1/sub-url-2/entity-id", "method": "PATCH", "payload": {"param2": "value2"}},
        {"url": "/api/v1/sub-url-3/entity-id", "method": "DELETE"},
    ]
    responses = []

    for sub_req_data in sub_requests:
        payload = sub_req_data.get("payload")

        sub_req = request.clone(method=sub_req_data["method"], rel_url=sub_req_data["url"]) # clone root request with new params

        if payload:
            body = json.dumps(payload).encode()
            sub_req._read_bytes = body # now `await sub_req.json()` will return `body`
            sub_req._payload.unread_data(body) # feed body to sub request to replace its `content` property with `body`

        route_info = await request.app.router.resolve(sub_req) # resolve a router for the sub request
        sub_req._match_info = route_info # it should match

        sub_resp = await route_info.handler(sub_req) # call router handler with the sub request

        try:
            sub_resp_body = json.loads(sub_resp.text) # read sub response
        except json.JSONDecodeError:
            sub_resp_body = {}

        response_payload = {"code": sub_resp.status, "payload": sub_resp_body} # fill sub response payload
        responses.append(response_payload)

    return json_response({"data": responses}) # return all payloads from sub requests