Google Firebase Cloud Functions: Android app's call to backend which calls `siteverify` actually requires a billing account to be used

Question

I use Google Firebase Cloud Functions to host the following script to check whether the ReCaptcha typed the user of my Android app is correct or not. The idea is that after the user types the captcha, the app calls the Cloud Functions' script (hosted in Google servers). The latter then calls itself the following URL with a POST request: https://www.google.com/recaptcha/api/siteverify.

Problem: in the Google servers' logs, I've found the following error:

Billing account not configured. External network is not accessible and quotas are severely limited. Configure billing account to remove these restrictions

Error: Error: getaddrinfo EAI_AGAIN www.google.com:443
    at Request._callback (/srv/index.js:20:10)
    at self.callback (/srv/node_modules/request/request.js:185:22)
    at emitOne (events.js:116:13)
    at Request.emit (events.js:211:7)
    at Request.onRequestError (/srv/node_modules/request/request.js:881:8)
    at emitOne (events.js:116:13)
    at ClientRequest.emit (events.js:211:7)
    at TLSSocket.socketErrorListener (_http_client.js:401:9)
    at emitOne (events.js:116:13)
    at TLSSocket.emit (events.js:211:7)

The backend script, hosted in Google Cloud Functions' servers, is the following:

const functions = require('firebase-functions');
const request2 = require('request');

/**
 * Verifies a Recaptcha filled by the user in his Android app.
 * 1. Success: returns the JSON response
 * 2. Failure: throws the error
 **/
exports.verifyRecaptcha = functions.https.onRequest((request, response) => {

    const user_response_token = request.query.user_response_token;
    if(user_response_token === '') {
        throw new functions.https.HttpsError('invalid-argument', 'The function must be called with an adequat user response token.');
    }

    const remote_url = 'https://www.google.com/recaptcha/api/siteverify';
    const secret = '';
    request2.post({url: remote_url, form:{secret: secret, response: user_response_token}}, function(error, response, body) {
        if(error) {
            throw new functions.https.HttpsError('unknown', error);
        }

        if(!response.statusCode !== 200) {
            throw new functions.https.HttpsError('unknown', 'Something went wrong. Status code: ' + response.statusCode + '.');
        }

        if(!body.success) {
            throw new functions.https.HttpsError('unknown', 'Unable to verify this captcha.');
        }

        return response;
    });

});

My question is: Is there any way to request this URL without having to create a billing account?

The URL you call is of a Google service, so it should work on the free plan. Most likely that URL pattern is just missing from the list of allowed URLs. Please [file a bug report](https://firebase.google.com/support/contact/bugs-features/). — Frank van Puffelen, Nov 21 '19 at 18:14
@FrankvanPuffelen From a Firebase dev: this issue is already known and they are working on it. But they can't tell me when it will be solved. — JarsOfJam-Scheduler, Nov 23 '19 at 09:07

robsiemb · Accepted Answer · 2019-11-21T19:52:04.067

1

Edit: As Frank points out in the comments, I missed that this was an internal URL, and the message is always displayed for the free plan, even though the requests should work. If the request isn't working, then a bug should be filed.

My answer was for a non-Google (e.g. external) URL, which I'll leave in place below (as it will allow you to bypass the check while the bug is resolved).

No. You need a billing account to make external network requests from Cloud Functions. See the Cloud Functions Section of the pricing page.

Just configuring a billing account however still allows you to take advantage of the free tier limits of the Spark plan. There is no actual cost incurred just for making an external network request.

edited Nov 21 '19 at 19:52

answered Nov 21 '19 at 16:59

robsiemb

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I have the Spark plan. Is it normal if it gives this error thus? – JarsOfJam-Scheduler Nov 21 '19 at 17:06
> Google services only + Invocations: 125K/month" – JarsOfJam-Scheduler Nov 21 '19 at 17:07
1

Yes, this is the error you get when you make the requests with the spark plan. Configuring a billing account basically puts you on the Blaze plan (but you still get the free tier limits of the spark plan). As I understand it, you get 5GB of outbound networking from cloud functions [free](https://cloud.google.com/functions/pricing#networking) -- same as the flame plan. – robsiemb Nov 21 '19 at 17:08
1

@robsiemb The warning is **always** shown for projects on the free plan, even when they only make calls to Google-owned services. – Frank van Puffelen Nov 21 '19 at 18:42
Blast, you're right, I missed that URL, thank you. I'll edit the answer. – robsiemb Nov 21 '19 at 19:28
@robsiemb From a Firebase dev: this issue is already known and they are working on it. But they can't tell me when it will be solved. – JarsOfJam-Scheduler Nov 23 '19 at 09:07

Google Firebase Cloud Functions: Android app's call to backend which calls `siteverify` actually requires a billing account to be used

1 Answers1