Box AI for HubsをTeamsから使えるように連携させてみた話

import os
import json
import logging
import jwt
import requests
import uuid
import time

import azure.functions as func

logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)

app = func.FunctionApp(http_auth_level=func.AuthLevel.FUNCTION)

@app.route(route="<関数名>")
def <関数名>(req: func.HttpRequest) -> func.HttpResponse:
    logger.info('Python HTTP trigger function processed a request.')

    try:
        # 環境変数からJWT認証に必要なパラメータを取得
        client_id = os.environ.get('BOX_CLIENT_ID')
        client_secret = os.environ.get('BOX_CLIENT_SECRET')
        private_key = os.environ.get('BOX_PRIVATE_KEY')
        public_key_id = os.environ.get('BOX_PUBLIC_KEY_ID')
        enterprise_id = os.environ.get('BOX_ENTERPRISE_ID')

        if not all([client_id, client_secret, private_key, public_key_id, enterprise_id]):
            missing_vars = [
                name for name, value in {
                    'BOX_CLIENT_ID': client_id,
                    'BOX_CLIENT_SECRET': client_secret,
                    'BOX_PRIVATE_KEY': private_key,
                    'BOX_PUBLIC_KEY_ID': public_key_id,
                    'BOX_ENTERPRISE_ID': enterprise_id
                }.items() if not value
            ]
            logger.error(f"Missing required environment variables: {', '.join(missing_vars)}")
            return func.HttpResponse(
                f"Missing one or more required environment variables: {', '.join(missing_vars)}. Please check your Azure Function App settings.",
                status_code=400
            )

        private_key = private_key.replace('\\n', '\n')

        # JWTクレームの作成
        jwt_body_claim = {
            "iss": client_id,
            "sub": enterprise_id,
            "box_sub_type": "enterprise",
            "aud": "https://api.box.com/oauth2/token",
            "jti": uuid.uuid4().hex,
            "exp": int(time.time()) + 60
        }

        logger.info(f"Generated JWT Claims: {jwt_body_claim}")

        # JWTのエンコード (RS512アルゴリズムを使用)
        jwt_token = jwt.encode(
            jwt_body_claim,
            private_key,
            algorithm="RS512",
            headers={"kid": public_key_id}
        )
        logger.info("JWT Token successfully encoded.")

        token_url = "https://api.box.com/oauth2/token"
        payload = {
            "grant_type": "urn:ietf:params:oauth:grant-type:jwt-bearer",
            "assertion": jwt_token,
            "client_id": client_id,
            "client_secret": client_secret
        }

        logger.info(f"Requesting access token from {token_url}...")
        response = requests.post(token_url, data=payload)


        if response.status_code != 200:
            logger.error(f"Box API responded with status {response.status_code}. Response content: {response.text}")
            return func.HttpResponse(
                f"Failed to retrieve access token from Box API. Status: {response.status_code}, Details: {response.text}",
                status_code=response.status_code
            )


        token_data = response.json()
        access_token = token_data.get('access_token')

        if access_token:
            logger.info("Access token successfully obtained.")
            return func.HttpResponse(
                json.dumps({"access_token": access_token}),
                mimetype="application/json",
                status_code=200
            )
        else:
            logger.error(f"Access token not found in Box API response: {token_data}")
            return func.HttpResponse(
                "Failed to retrieve access token.",
                status_code=500
            )

    except requests.exceptions.RequestException as e:
        logger.error(f"HTTP Request to Box API failed: {e}", exc_info=True)
        return func.HttpResponse(
            f"Error communicating with Box API: {e}",
            status_code=500
        )
    except jwt.PyJWTError as e:
        logger.error(f"JWT encoding failed: {e}", exc_info=True)
        return func.HttpResponse(
            f"Error encoding JWT for Box authentication: {e}",
            status_code=500
        )
    except Exception as e:
        logger.error(f"An unexpected error occurred in the function: {e}", exc_info=True)
        return func.HttpResponse(
            f"An internal server error occurred: {e}",
            status_code=500
        )