functions-samples/delete-unused-accounts-cron/README.md

Periodically delete unused accounts.

This sample demonstrates how to delete the accounts of users who have not signed-in in the last month.

Functions Code

See file functions/index.js for the code.

Cloud Functions does not natively supports cron jobs. We are working around this by executing the code as an HTTPS triggered function. Then simply use an external service to periodically "ping" the URL.

Here is a non-exhaustive list of external services for cron jobs:

• https://www.setcronjob.com/
• https://cron-job.org/
• https://www.easycron.com/
• https://zapier.com/zapbook/webhook/

The dependencies are listed in functions/package.json.

Trigger rules

The function triggers when the HTTP URL of the Function is requested.

Deploy and test

Set the cron.key Google Cloud environment variables to a randomly generated key, this will be used to authorize requests coming from the 3rd-party cron service. For this use:

firebase functions:config:set cron.key="YOUR-KEY"

You can generate a random key, for instance, by running:

npm install -g crypto
node -e "console.log(require('crypto').randomBytes(20).toString('hex'))"

To set up the sample:

• Create a Firebase Project using the Firebase Developer Console
• Download this sample e.g. git clone https://github.com/firebase/functions-samples
• Enter the sample directory cd functions-samples/delete-unused-accounts-cron
• Setup the sample with your project firebase use --add and follow the instructions.
• Install node dependencies of your Functions cd functions; npm install; cd -
• Deploy your project using firebase deploy.
• Open an account with a 3rd party cron service (e.g. www.setcronjob.com, cron-job.org, www.easycron.com, Zapier ...) and setup a daily cron job to hit the URL (don't forget to change <YOUR-KEY> and <PROJECT-ID>):

https://us-central1-<PROJECT-ID>.cloudfunctions.net/accountcleanup?key=<YOUR-KEY>