Cloud Functions无法从Google Compute Engine元数据服务检索令牌

Question

我的云功能不断产生此错误。

failed with error: ("Failed to retrieve
http://metadata.google.internal/computeMetadata/v1/instance/service-accounts/{service-account}/token
from the Google Compute Enginemetadata service. Status: 500
Response:\nb'Could not fetch URI
/computeMetadata/v1/instance/service-accounts/{service-account}/token\\n'",
<google.auth.transport.requests._Response object at 0x2a6b7bacebe0>)

我创建了一个需要与Firebase Firestore连接的云功能。我还创建了一个与“编辑者”角色绑定的服务帐户。我不知道为什么它仍然无法工作。

我的源代码。

import base64

import firebase_admin
import requests
from firebase_admin import firestore


def api(request):
    # Get client id and client token from header?

    request_json = request.get_json()  # Get data

    firebase_admin.initialize_app()
    db = firestore.client()

    return "Successful"