App Engine Cron with Google Cloud Functions for Firebase
Google App Engine provides a Cron service. Using this service for scheduling and Google Cloud Pub/Sub for distributed messaging, you can build an application to reliably schedule tasks which can trigger Google Cloud Functions.
This sample contains two components:
An App Engine application, that uses App Engine Cron Service to relay cron messages to Cloud Pub/Sub topics.
A sample Cloud Function which triggers hourly.
By default this sample triggers hourly, daily, and weekly. If you want to customize this schedule for your app then you can modify the cron.yaml.
For details on configuring this, please see the cron.yaml Reference in the App Engine documentation.
The overview for configuring and running this sample is as follows:
If you don’t already have one, create a Google Account.
Create a Developers Console project.
2. Clone this repository
To clone the GitHub repository to your computer, run the following command:
$ git clone https://github.com/firebase/functions-cron
Change directories to the
functions-cron directory. The exact path
depends on where you placed the directory when you cloned the sample files from
$ cd functions-cron
Leave the default cron.yaml as is for now to run through the sample.
3. Deploy to App Engine
- Configure the
gcloudcommand-line tool to use the project your Firebase project.
$ gcloud config set project <your-project-id>
- Change directory to
$ cd appengine/
- Install the Python dependencies
$ pip install -t lib -r requirements.txt
- Create an App Engine App
$ gcloud app create
- Deploy the application to App Engine.
$ gcloud app deploy app.yaml \cron.yaml
- Open Google Cloud Logging and in the right dropdown select "GAE Application". If you don't see this option, it may mean that App Engine is still in the process of deploying.
- Look for a log entry calling
/_ah/start. If this entry isn't an error, then you're done deploying the App Engine app.
3. Deploy to Google Cloud Functions for Firebase
- Ensure you're back the root of the repository (
cd .., if you're coming from Step 2)
- Deploy the sample
hourly_jobfunction to Google Cloud Functions
$ firebase deploy --only functions --project <FIREBASE_PROJECT_ID>
Warning: This will remove any existing functions you have deployed.
If you have existing functions, move the example from functions/index.js
into your project's
4. Verify your Cron Jobs
We can verify that our function is wired up correctly by opening the Task Queue tab in AppEngine and clicking on Cron Jobs. Each of these jobs has a Run Now button next to it.
The sample functions we deployed only has one function:
hourly_job. To trigger
this job, let's hit the Run Now button for the
Then, go to your terminal and run...
$ firebase functions:log --project <FIREBASE_PROJECT_ID>
You should see a successful
console.log from your
5. You're Done!
Your cron jobs will now "tick" along forever. As I mentioned above, you're not
limited to the
weekly-tick that are included
in the AppEngine app. You can add more scheduled functions by modifying the cron.yaml file and re-deploying.
Copyright 2017 Google Inc. All Rights Reserved.
Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at
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