AWS Lambda 使用 firebase-admin initializeApp 超时

Question

我使用 Lambda 来处理 Firebase 消息。我参考 this。但是 lambda 函数仍然超时，因为它无法连接到 google 服务器。

Handler.js

/ [START imports]
const firebase = require('firebase-admin');
const serviceAccount = require("../serviceAccount.json");

module.exports.message = (event, context, callback) => {
  context.callbackWaitsForEmptyEventLoop = false;  
  const registrationToken = "xxxxxxx";

  const payload = {
    data: {
      score: "850",
      time: "2:45"
    }
  };

  // [START initialize]
  if(firebase.apps.length == 0) {   // <---Important!!! In lambda, it will cause double initialization.
    firebase.initializeApp({
      credential: firebase.credential.cert(serviceAccount),
      databaseURL: 'https://messaging-xxxxx.firebaseio.com'
    });
  }

  // Send a message to the device corresponding to the provided
  // registration token.
  firebase.messaging().sendToDevice(registrationToken, payload)
    .then(function(response) {
      // See the MessagingDevicesResponse reference documentation for
      // the contents of response.
      console.log("Successfully sent message:", response);
      callback(null, {
        statusCode: 200,
        body: JSON.stringify("Successful!"),
      });
    })
    .catch(function(error) {
      console.log("Error sending message:", error);
      callback(null, {
        statusCode: 500,
        body: JSON.stringify({
          "status": "error",
          "message": error
        })
      })
    });
};

CloudWatch

[Error: Credential implementation provided to initializeApp() via the "credential" property failed to fetch a valid Google OAuth2 access token with the following error: "connect ETIMEDOUT 172.217.26.45:443".]

但我在我的 ec2 上使用与 运行 相同的 serviceAccount.json 和工作查找。 有人遇到过这个吗？

Answer 1

经过几个小时的挣扎，我终于找到了原因。 因为我的Lambda使用VPC连接RDS，而VPC的网络接口只有私有IP。

AWS document:

When you add VPC configuration to a Lambda function, it can only access resources in that VPC. If a Lambda function needs to access both VPC resources and the public Internet, the VPC needs to have a Network Address Translation (NAT) instance inside the VPC.

所以我需要在 VPC 内部创建 NAT。 我按照这个 Blog 解决了问题。