User can keep their commit email private

The private commit email is automatically generated in the format:
id-username@noreply.HOSTNAME

GitLab instance admins are able to change the HOSTNAME portion,
that defaults to Gitlab's hostname, to whatever they prefer.

1 files changed, 28 insertions, 0 deletions

diff --git a/lib/gitlab/private_commit_email.rb b/lib/gitlab/private_commit_email.rb
new file mode 100644
index 00000000000..bade2248ccd
--- /dev/null
+++ b/lib/gitlab/private_commit_email.rb
@@ -0,0 +1,28 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module PrivateCommitEmail
+    TOKEN = "_private".freeze
+
+    class << self
+      def regex
+        hostname_regexp = Regexp.escape(Gitlab::CurrentSettings.current_application_settings.commit_email_hostname)
+
+        /\A(?<id>([0-9]+))\-([^@]+)@#{hostname_regexp}\z/
+      end
+
+      def user_id_for_email(email)
+        match = email&.match(regex)
+        return unless match
+
+        match[:id].to_i
+      end
+
+      def for_user(user)
+        hostname = Gitlab::CurrentSettings.current_application_settings.commit_email_hostname
+
+        "#{user.id}-#{user.username}@#{hostname}"
+      end
+    end
+  end
+end