How to oAuth Google API from Lambda AWS?

Question

I am building Alexa Skill for Google calendar. The client side code works as expected on local machine because I can authenticate the local machine using the link. But, when I deploy the code on AWS Lambda there is no way that I can authenticate as I cannot input code via AWS console.

I am getting trouble in setting up authentication of Google Calendar API when deployed on AWS lambda.

This documentation doesn't help much to me Google Implementing Server Side Authentication

Answer 1

You should create a service account. Those are designed especially for server-to-server communication. Documentation can be found here: https://developers.google.com/identity/protocols/OAuth2ServiceAccount

The problems with the solutions from other answers are:

• API keys are insecure
• Access tokens (e.g. obtained by the CLI command gcloud auth print-access-token) expire. Since Lambdas are stateless, there's no way to store a token temporarily and refresh it when it's expired.

Answer 2

I know this is late, but after struggling a lot with this problem, I found a solution. Do google auth with JWT

const {google} = require('googleapis');


const key ={
 client_email: process.env.CLIENT_EMAIL,
 private_key: process.env.PRIVATE_KEY,
}

const auth = new google.auth.JWT(
  key.client_email,
  null,
  key.private_key,
  ["https://www.googleapis.com/auth/analytics.readonly"],
  null
);

google.options({auth});