reCAPTCHA

GitLab leverages Google's reCAPTCHA to protect against spam and abuse. GitLab displays the CAPTCHA form on the sign-up page to confirm that a real user, not a bot, is attempting to create an account.

Configuration

To use reCAPTCHA, first you must create a site and private key.

1. Go to the URL: https://www.google.com/recaptcha/admin.
2. Fill out the form necessary to obtain reCAPTCHA v2 keys.
3. Log in to your GitLab server, with administrator credentials.
4. Go to Reporting Applications Settings in the Admin Area (admin/application_settings/reporting).
5. Fill all reCAPTCHA fields with keys from previous steps.
6. Check the Enable reCAPTCHA checkbox.
7. Save the configuration.
8. Change the first line of the #execute method in app/services/spam/spam_verdict_service.rb to return CONDITONAL_ALLOW so that the spam check short-circuits and triggers the response to return recaptcha_html.

NOTE: Make sure you are viewing an issuable in a project that is public, and if you're working with an issue, the issue is public.

Enabling reCAPTCHA for user logins via passwords

By default, reCAPTCHA is only enabled for user registrations. To enable it for user logins via passwords, the X-GitLab-Show-Login-Captcha HTTP header must be set. For example, in NGINX, this can be done via the proxy_set_header configuration variable:

proxy_set_header X-GitLab-Show-Login-Captcha 1;

In Omnibus GitLab, this can be configured via /etc/gitlab/gitlab.rb:

nginx['proxy_set_headers'] = { 'X-GitLab-Show-Login-Captcha' => '1' }