Azure Function中HTTP请求体解析错误的处理与优化

import os
import base64
import json
import jwt
from hashlib import md5
from datetime import datetime, timedelta
import azure.functions as func
import logging
import requests
from http.client import IncompleteRead # 导入IncompleteRead异常

# 配置日志记录
logging.basicConfig(level=logging.INFO)

# Azure Function HTTP触发器入口
@app.route(route="webhooks/baas", auth_level=func.AuthLevel.ANONYMOUS)
def webhook_decoder_baas(req: func.HttpRequest) -> func.HttpResponse:
    try:
        # 导入并解码用于发送信息的私钥
        private_key = os.environ.get("private_key_baas")
        if not private_key:
            logging.error("Environment variable 'private_key_baas' not set.")
            return func.HttpResponse("Internal server error: Missing private key.", status_code=500)
        private_key_baas = base64.b64decode(private_key).decode("utf-8")

        # 声明用于解码接收到的webhook的公钥
        qi_public_key = '''-----BEGIN PUBLIC KEY-----
        ... :)
        -----END PUBLIC KEY-----'''

        # 获取AUTHORIZATION头部
        authorization = req.headers.get("AUTHORIZATION")
        if not authorization:
            logging.error("AUTHORIZATION header not provided.")
            return func.HttpResponse("AUTHORIZATION header not provided.", status_code=400)

        # 尝试读取请求体并解析JSON
        body_json = None
        try:
            body = req.get_body() # 获取原始字节流
            if not body: # 检查请求体是否为空
                logging.error("Empty or missing request body.")
                return func.HttpResponse("Empty or missing request body.", status_code=400)

            body_json = json.loads(body) # 显式解析JSON
        except ValueError as json_error:
            # 捕获JSON解析错误
            logging.error(f"Error parsing JSON from request body: {str(json_error)}")
            return func.HttpResponse("Error parsing JSON from request body.", status_code=400)
        except IncompleteRead as incomplete_read_error:
            # 捕获请求体不完整错误
            logging.error(f"Incomplete read error while processing request body: {str(incomplete_read_error)}")
            return func.HttpResponse("Incomplete read error while processing request body.", status_code=400)
        except Exception as e:
            # 捕获读取请求体时的其他未知错误
            logging.error(f"Unexpected error reading or parsing request body: {str(e)}")
            return func.HttpResponse("An unexpected error occurred while processing the request body.", status_code=400)

        # 解码JWT令牌
        try:
            decoded_header = jwt.decode(token=authorization, key=qi_public_key, algorithms=['ES512']) # 明确指定算法
        except jwt.exceptions.ExpiredSignatureError:
            logging.error("JWT token has expired.")
            return func.HttpResponse("Unauthorized: Token expired.", status_code=401)
        except jwt.exceptions.InvalidTokenError as jwt_error:
            logging.error(f"Invalid JWT token: {str(jwt_error)}")
            return func.HttpResponse(f"Unauthorized: Invalid token. {str(jwt_error)}", status_code=401)
        except Exception as e:
            logging.error(f"Error decoding JWT token: {str(e)}")
            return func.HttpResponse("Unauthorized: Token decoding failed.", status_code=401)

        # 验证接收到的数据
        # 将多个assert语句放在一个try-except AssertionError块中，提高代码简洁性
        try:
            assert decoded_header.get("method") == "POST", "Error in the sending method, a different method than POST was used."
            assert decoded_header.get("payload_md5") == md5(json.dumps(body_json).encode()).hexdigest(), "Payload hash does not match the expected one."

            timestamp_str = decoded_header.get("timestamp")
            if not timestamp_str:
                raise AssertionError("Timestamp is missing from JWT header.")
            timestamp = datetime.strptime(timestamp_str, "%Y-%m-%dT%H:%M:%S.%fZ")

            # 检查时间戳是否在10分钟窗口内
            current_utc = datetime.utcnow()
            if not ((current_utc - timedelta(minutes=5)) < timestamp < (current_utc + timedelta(minutes=5))):
                raise AssertionError("Error in sending timestamp, outside the 10-minute limit.")

        except AssertionError as assertion_error:
            logging.error(f"Assertion error during data validation: {str(assertion_error)}")
            return func.HttpResponse(str(assertion_error), status_code=400)
        except ValueError as date_parse_error:
            logging.error(f"Error parsing timestamp: {str(date_parse_error)}")
            return func.HttpResponse("Invalid timestamp format in token.", status_code=400)

        # 将接收到的数据转换为Python对象（已在前面完成）
        objeto_payload = body_json

        # 验证接收到的数据是否符合所需要求
        if (
            objeto_payload.get("webhook_type") == "bank_slip.status_change" and 
            (objeto_payload.get("status") == "payment_notice" or objeto_payload.get("status") == "notary_office_payment_notice")
        ):
            # 提取所需数据
            bank_slip_key = objeto_payload.get("data", {}).get("bank_slip_key")
            paid_amount = objeto_payload.get("data", {}).get("paid_amount")

            # 创建新的Python对象
            payload_output = {
                key: objeto_payload[key] for key in ["status"]
            }
            payload_output['Paid amount'] = paid_amount
            payload_output['Query key of the title'] = bank_slip_key

            # 目标URL
            url = "https://nerowebhooks.azurewebsites.net/api/information/send"

            # 加密要发送的数据
            token = jwt.encode(payload_output, private_key_baas, algorithm='ES512')

            # 创建发送头部
            headers = {
                'SIGNATURE': token,
                'Content-Type': 'application/json' # 明确指定内容类型
            }

            # 发送提取的信息
            response = requests.post(url, headers=headers, json=payload_output)
            response.raise_for_status() # 如果请求失败（非2xx状态码），则抛出HTTPError

            logging.info(f"Successfully processed webhook. Sent data: {payload_output}")
            return func.HttpResponse("Webhook received and processed successfully!", status_code=200)
        else:
            logging.info("Webhook received successfully, but it won't be handled at the moment (conditions not met).")
            return func.HttpResponse("Webhook received successfully, but it won't be handled at the moment!", status_code=200)

    except requests.exceptions.RequestException as req_error:
        # 捕获发送POST请求时的网络或HTTP错误
        logging.error(f"Error sending data to external service: {str(req_error)}")
        return func.HttpResponse(f"Error sending data to external service: {str(req_error)}", status_code=500)
    except Exception as e:
        # 捕获所有其他未预料的内部错误
        logging.error(f"An unhandled internal error occurred: {str(e)}")
        return func.HttpResponse(f"An internal server error occurred: {str(e)}", status_code=500)