Authorize google service account using AWS Lambda/API Gateway - amazon-web-services

Question

My express server has a credentials.json containing credentials for a google service account. These credentials are used to get a jwt from google, and that jwt is used by my server to update google sheets owned by the service account.
var jwt_client = null;
// load credentials form a local file
fs.readFile('./private/credentials.json', (err, content) => {
if (err) return console.log('Error loading client secret file:', err);
// Authorize a client with credentials, then call the Google Sheets API.
authorize(JSON.parse(content));
});
// get JWT
function authorize(credentials) {
const {client_email, private_key} = credentials;
jwt_client = new google.auth.JWT(client_email, null, private_key, SCOPES);
}
var sheets = google.sheets({version: 'v4', auth: jwt_client });
// at this point i can call google api and make authorized requests
The issue is that I'm trying to move from node/express to npm serverless/aws. I'm using the same code but getting 403 - forbidden.
errors:
[ { message: 'The request is missing a valid API key.',
domain: 'global',
reason: 'forbidden' } ] }
Research has pointed me to many things including: AWS Cognito, storing credentials in environment variables, custom authorizers in API gateway. All of these seem viable to me but I am new to AWS so any advice on which direction to take would be greatly appreciated.

Answer 1

it is late, but may help someone else. Here is my working code.
const {google} = require('googleapis');
const KEY = require('./keys');
const _ = require('lodash');
const sheets = google.sheets('v4');
const jwtClient = new google.auth.JWT(
KEY.client_email,
null,
KEY.private_key,
[
'https://www.googleapis.com/auth/drive',
'https://www.googleapis.com/auth/drive.file',
'https://www.googleapis.com/auth/spreadsheets'
],
null
);
async function getGoogleSheetData() {
await jwtClient.authorize();
const request = {
// The ID of the spreadsheet to retrieve data from.
spreadsheetId: 'put your id here',
// The A1 notation of the values to retrieve.
range: 'put your range here', // TODO: Update placeholder value.
auth: jwtClient,
};
return await sheets.spreadsheets.values.get(request)
}
And then call it in the lambda handler. There is one thing I don't like is storing key.json as file in the project root. Will try to find some better place to save.