AWS Lambda using firebase-admin initializeApp timeout

问题

I use Lambda to Firebase message. I ref this. But the lambda function still timeout because it cannot connect to google server.

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".]

But I use same serviceAccount.json to run on my ec2 and work find. Does someone encounter this?

回答1:

After a couple hours struggling, I finally find the reason. Because my Lambda using VPC to connect RDS and the network interface of VPC only have private 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.

So I need to create NAT inside the VPC. I follow this Blog and problem solved.

来源：https://stackoverflow.com/questions/42312496/aws-lambda-using-firebase-admin-initializeapp-timeout