Switching delete unused accounts to scheduled functions (firebase#567)

Author: jamesdaniels

delete-unused-accounts-cron/README.md

@@ -7,37 +7,12 @@ This sample demonstrates how to delete the accounts of users who have not signed
 
 See the file [functions/index.js](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://cloud.google.com/scheduler/
- - https://cron-job.org/
- - https://www.setcronjob.com/
- - https://www.easycron.com/
- - https://zapier.com/zapbook/webhook/
+**Note:** This function uses Cloud Scheduler and Pub/Sub, which can have associated costs. Your project must be on the Blaze payment plan as these features require billing information. See the [Cloud Scheduler pricing page](https://cloud.google.com/scheduler/pricing) for more information.
 
 The dependencies are listed in [functions/package.json](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:
-
-```bash
-firebase functions:config:set cron.key="YOUR-KEY"
-```
-
-You can generate a random key, for instance, by running:
-
-```bash
-node -e "console.log(require('crypto').randomBytes(20).toString('hex'))"
-```
-
 To set up the sample:
 
  - Create a Firebase Project using the [Firebase Developer Console](https://console.firebase.google.com)
@@ -46,8 +21,4 @@ To set up the sample:
  - 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](https://zapier.com/zapbook/webhook/) ...) 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>
- ```
+ - The pubsub task should then run once a day and delete any inactive users. You can manually run the task by [navigating to Cloud Scheduler in the Google Cloud Platform Console](https://console.cloud.google.com/cloudscheduler).

delete-unused-accounts-cron/functions/index.js

@@ -20,35 +20,20 @@ const admin = require('firebase-admin');
 admin.initializeApp();
 const promisePool = require('es6-promise-pool');
 const PromisePool = promisePool.PromisePool;
-const secureCompare = require('secure-compare');
 // Maximum concurrent account deletions.
 const MAX_CONCURRENT = 3;
 
 /**
- * When requested this Function will delete every user accounts that has been inactive for 30 days.
- * The request needs to be authorized by passing a 'key' query parameter in the URL. This key must
- * match a key set as an environment variable using `firebase functions:config:set cron.key="YOUR_KEY"`.
+ * Run once a day at midnight, to cleanup the users
+ * Manually run the task here https://console.cloud.google.com/cloudscheduler
  */
-exports.accountcleanup = functions.https.onRequest(async (req, res) => {
-  const key = req.query.key;
-
-  // Exit if the keys don't match.
-  if (!secureCompare(key, functions.config().cron.key)) {
-    console.log('The key provided in the request does not match the key set in the environment. Check that', key,
-        'matches the cron.key attribute in `firebase env:get`');
-    res.status(403).send('Security key does not match. Make sure your "key" URL query parameter matches the ' +
-        'cron.key environment variable.');
-    return null;
-  }
-  
+exports.accountcleanup = functions.pubsub.schedule('every day 00:00').onRun(async context => {
   // Fetch all user details.
   const inactiveUsers = await getInactiveUsers();
   // Use a pool so that we delete maximum `MAX_CONCURRENT` users in parallel.
   const promisePool = new PromisePool(() => deleteInactiveUser(inactiveUsers), MAX_CONCURRENT);
   await promisePool.start();
   console.log('User cleanup finished');
-  res.send('User cleanup finished');
-  return null;
 });
 
 /**

delete-unused-accounts-cron/functions/package.json

@@ -3,9 +3,8 @@
   "description": "Periodically delete unused Firebase accounts",
   "dependencies": {
     "es6-promise-pool": "^2.4.4",
-    "secure-compare": "^3.0.1",
     "firebase-admin": "~7.1.1",
-    "firebase-functions": "^2.2.1"
+    "firebase-functions": "^2.3.0"
   },
   "devDependencies": {
     "eslint": "^4.13.1",