Firebase 管理 SDK：未获取访问令牌

Question

目标是让我的 Express 服务器使用 Firebase Cloud Messaging (FCM) 发送推送通知。

问题是admin SDK的初始化似乎不起作用。代码是用 JavaScript 编写的，节点版本是 10.16.0，firebase-admin 版本是 8.3.0，服务器在最新的 Ubuntu 上运行。

我按照 firebase 指南设置了管理 SDK： https ://firebase.google.com/docs/admin/setup#initialize_the_sdk

设置了 GOOGLE_APPLICATION_CREDENTIALS 环境变量，并尝试使用该变量打开文件：

nano $GOOGLE_APPLICATION_CREDENTIALS

一次

admin.messaging().send(message)

被调用时，会抛出以下错误：

Error sending message: { Error: Credential implementation provided to initializeApp() via the "credential" property failed to fetch a valid Google OAuth2 access token with the following error: "Error fetching access token: Error while making request: getaddrinfo ENOTFOUND metadata.google.internal metadata.google.internal:80. Error code: ENOTFOUND".
    at FirebaseAppError.FirebaseError [as constructor] (/local/home/user/node_modules/firebase-admin/lib/utils/error.js:42:28)
    at FirebaseAppError.PrefixedFirebaseError [as constructor] (/local/home/user/node_modules/firebase-admin/lib/utils/error.js:88:28)
    at new FirebaseAppError (/local/home/user/node_modules/firebase-admin/lib/utils/error.js:122:28)
    at /local/home/user/node_modules/firebase-admin/lib/firebase-app.js:121:23
    at process._tickCallback (internal/process/next_tick.js:68:7)
  errorInfo:
   { code: 'app/invalid-credential',
     message:
      'Credential implementation provided to initializeApp() via the "credential" property failed to fetch a valid Google OAuth2 access token with the following error: "Error fetching access token: Error while making request: getaddrinfo ENOTFOUND metadata.google.internal metadata.google.internal:80. Error code: ENOTFOUND".' },
  codePrefix: 'app' }

实施过程非常严格地遵循 firebase 指南。

类似的问题表明 Spark 计划不支持云功能。但据我了解，我正在尝试使用云消息传递而不是云功能。

我不知道出了什么问题。特别是因为它与指南中的代码非常相似。除了 firebase-admin 之外，我还需要安装其他一些 firebase 组件吗？

服务器代码：

const express = require('express');


//firebase for notifications
const admin = require('firebase-admin');


admin.initializeApp({
    projectId: <projectId>,
    credential: admin.credential.applicationDefault(),
    databaseURL: "https://<projectId>.firebaseio.com"
});

// server set up removed


io.on('connection', socket => {

    socket.on('notification', (target, message) => {
        // This log is printed
        console.log("got notification for: ", target)
        // target = registration token comes from the client FCM SDKs.
        if (typeof (target) === "string") {
            sendNotifiaction(target, message)
        }
    });

});

function sendNotifiaction(registrationToken, message) {
    // This registration token comes from the client FCM SDKs.
    message.token = registrationToken

    // Send a message to the device corresponding to the provided
    // registration token.
    admin.messaging().send(message)
        .then((response) => {
            // Response is a message ID string.
            console.log('Successfully sent message:', response);
        })
        .catch((error) => {
            // Error catched here
            console.log('Error sending message:', error);
        });
}

服务帐户密钥（文件路径 = $GOOGLE_APPLICATION_CREDENTIALS）。某些字段明显被省略。

{
  "type": "service_account",
  "project_id": "..",
  "private_key_id": "..",
  "private_key": "-----BEGIN PRIVATE KEY-----.."
  "client_email": "firebase-adminsdk-.....iam.gserviceaccount.com",
  "client_id": "...",
  "auth_uri": "https://accounts.google.com/o/oauth2/auth",
  "token_uri": "https://oauth2.googleapis.com/token",
  "auth_provider_x509_cert_url": "https://www.googleapis.com/oauth2/v1/certs",
  "client_x509_cert_url": "https://www.googleapis.com/robot/v1/metadata/x509/firebase-adminsdk-......iam.gserviceaccount.com"
}

Answer 1

解决方案

我刚刚使用了 firebase 控制台（设置->服务帐户）提供的代码示例。

注意：我之前尝试过此操作，但没有成功：因此请检查路径是否正确以及您的服务器是否有权访问它。

var serviceAccount = require("path/to/serviceAccountKey.json");

admin.initializeApp({
  credential: admin.credential.cert(serviceAccount),
  databaseURL: "https://<ProjectId>.firebaseio.com"
});