Free Secure Login with Location Tracking – Apps Script

FREE019 is a login built to slow an attacker down and to leave a record of everyone who got in. Two things happen on a successful sign-in: the location it came from is written to the sheet, and that account is locked out of logging in again for the next two minutes.

The cooldown

Once an account has signed in, trying again immediately is refused with a message to wait two minutes and try again. The timer is per account, so one person's cooldown does not affect anybody else, and it lifts on its own. It is a simple, blunt throttle — the kind of thing that turns rapid repeated attempts from cheap into tedious, without any infrastructure behind it.

The location record

Every successful login writes the user ID, the time and the location it came from. When you look at the sheet you are not just seeing that somebody logged in, you are seeing where from — which is the detail that makes an unexpected entry noticeable. Worth knowing: the location is derived from the connection, so a VPN or a mobile network will report accordingly. The walkthrough shows exactly that, with the location changing as the presenter's VPN does.

Your site behind it

After login, the user lands on a main page you fill yourself. The walkthrough pastes an entire website's HTML into it and it renders, which is the point: this is a front door for something you have already built, not a dashboard you have to adopt.

Setting it up

Copy the sheet, change the sheet name in the one place the code refers to it, and deploy. The login screen is Bootstrap, so restyling it is ordinary CSS.