通过函数写入FireStore时发生FireBase错误:“7权限被拒绝:权限缺失或不足”

我正在尝试编写一个简单的firebase函数,用typescript将记录添加到firestore。代码的缩减版本为:

import * as admin from "firebase-admin";
import * as functions from "firebase-functions";

const config = functions.config();

admin.initializeApp(functions.config().firebase);
admin.database.enableLogging(true);

exports.subscriptions = functions.https.onRequest(
  async (req, res) => {
    try {
      const requestSubscription = req.body;
      const subscription = {
        subscription_id: requestSubscription.subscription_id,
        email: requestSubscription.email || ""
      };

      const id = subscription.subscription_id;
      const dbSubscriptions = admin.firestore().collection("subscriptions");
      await dbSubscriptions.doc(id).set(subscription);

      return res.status(200).send(`Success`);
    } catch (e) {
      console.error(e.stack);
      return res.status(500).send(`Error`);
    }
  }
);

这在本地可以正常工作。部署时,我会收到以下错误:

Error: 7 PERMISSION_DENIED: Missing or insufficient permissions.
    at Object.exports.createStatusError (/user_code/node_modules/firebase-admin/node_modules/grpc/src/common.js:87:15)
    at Object.onReceiveStatus (/user_code/node_modules/firebase-admin/node_modules/grpc/src/client_interceptors.js:1214:28)
    at InterceptingListener._callNext (/user_code/node_modules/firebase-admin/node_modules/grpc/src/client_interceptors.js:590:42)
    at InterceptingListener.onReceiveStatus (/user_code/node_modules/firebase-admin/node_modules/grpc/src/client_interceptors.js:640:8)
    at callback (/user_code/node_modules/firebase-admin/node_modules/grpc/src/client_interceptors.js:867:24)

我的函数/package.json文件是:

{
  "name": "functions",
  "scripts": {
    "lint": "tslint --project tsconfig.json",
    "build": "tsc",
    "serve": "npm run build && firebase serve --only functions",
    "shell": "npm run build && firebase functions:shell",
    "start": "npm run shell",
    "deploy": "firebase deploy --only functions",
    "logs": "firebase functions:log"
  },
  "main": "lib/index.js",
  "dependencies": {
    "express": "4.16.3",
    "firebase-admin": "5.12.1",
    "firebase-functions": "1.0.3"
  },
  "devDependencies": {
    "tslint": "^5.8.0",
    "typescript": "^2.5.3"
  },
  "private": true
}

我搜索此错误的唯一链接是这个未回答的问题: PERMISSION_DENIED Firestore CloudFunction TypeScript

我已经设置了我的FireStore规则,允许任何人也可以读写,即使上面使用的是admin,但它仍然不起作用。

有人能帮忙吗?