Firebase Callable function with JWT Authentication and Google Sheets V4 API - firebase

Question

I want to implement firebase callable function with JWT Authentication and fetching data from Google Sheet, using Google Sheets V4 API.
For test I tried to use Example Spreadsheet but Sheets API not activated for that Spreadsheet and I cloned it on my own drive and use it for testing.
References:
My code based on solution described in this question How to use Google sheets API while inside a google cloud function and Accessing Google APIs using Service account in Node.JS
Also I have got two important information: "Service Account".json and API Key. I save API Key in api_key.json but didn't find examples how to use it with Google Sheets V4 API:
{
key: "xxxxxx"
}
test() callable function which doesn't require any authentication works fine:
exports.test = functions.https.onCall((data, context) => {
return { text: data.text };
});
Calling test() function somewhere on client (in Browser):
function getTest() {
console.log("clicked getTest()");
var test = firebase.functions().httpsCallable('test');
test({text: '12345'}).then(function(result) {
console.log(result);
}).catch(function(error) {
console.log(error.code);
console.log(error.message);
});
}
Calling getData() somewhere on client (in Browser):
function requestData() {
console.log("clicked requestData()");
//https://firebase.google.com/docs/functions/callable
//getData() function described in functions/index.js
var getData = firebase.functions().httpsCallable('getData');
getData(null).then(function (result) {
// Read result of the Cloud Function.
console.log(result); //<------- Expected rows from Spreadsheet????
}).catch(function(error) {
console.log(error.code);
console.log(error.message);
});
}
**Thank you, F10. I corrected code.
index.js:
'use strict'
const functions = require('firebase-functions');
const { google } = require('googleapis');
var serviceAccount = require("./credentials/owner-service-account-gcloud.json");
function getJwt() {
// Define the required scopes.
var scopes = [
'https://www.googleapis.com/auth/spreadsheets'
];
return new google.auth.JWT(
serviceAccount.client_email,
null,
serviceAccount.private_key,
scopes
);
}
function getSpreadsheetDate(jwt) {
return new Promise((resolve, reject) => {
jwt.authorize((error, access_token) => {
if (error) {
console.log('Error in jwt.authorize: ' + error);
reject(error);
} else {
// access_token ready to use to fetch data and return to client
const sheets = google.sheets({ version: 'v4', access_token });
// set auth as a global default:
google.options({ auth: jwt }); //<----------------------
const request = {
auth: jwt,
spreadsheetId: 'xxxx',
range: 'Class Data!A2:E', //'Class Data!A2:E',
}
sheets.spreadsheets.values.get(request, (err, response) => {
console.log("inside: sheets.spreadsheets.values.get() -------------------------------");
if (err) {
console.log('The Sheets API returned an error: ' + err);
//The API returned an error: Error: API key not valid. Please pass a valid API key.
reject(err);
};
try {
var numRows = response.data.values ? response.data.values.length : 0;
console.log('%d rows retrieved.', numRows);
console.log("response.data:-------------------------------");
console.log(response.data.values);
resolve(response.data.values);
} catch (err) {
console.log("Error processing Sheets API response: " + err);
reject(err);
}
})
}
})
})
}
exports.getData = functions.https.onCall((data, context) => {
console.log("getData()---------------------------");
if (!context.auth) {
throw new functions.https.HttpsError('failed-precondition', 'The function must be called ' + 'while authenticated.');
} else {
console.log("context.auth ------------ OK");
const uid = context.auth.uid;
console.log(uid);
var jwt = getJwt();
console.log("getJwt() --------------- OK");
return getSpreadsheetDate(jwt); //<------------ Requested Spreadsheet's Data
}
})
exports.test = functions.https.onCall((data, context) => {
return { text: data.text };
});

Answer 1

There's a solution that uses googleapis instead of the auth library to do the authentication with JWT. Regarding your token inquiries, you could check the OAuth 2.0 for client-side web applications documentations, which explains the steps to do the authentication.