A Cron Connector for OpenFaaS

This is a cron event connector for OpenFaaS. This was built to provide a timer interface to trigger OpenFaaS functions. Also checkout OpenFaaS docs on cron for other methods on how you can run functions triggered by cron.

This project was forked from zeerorg/cron-connector to enable prompt updates and patches for end-users.

How to Use

You need to have OpenFaaS deployed first, see https://docs.openfaas.com to get started

Deploy using the Helm chart

The helm chart is available in the faas-netes repo.

For faasd, you can edit your docker-compose.yaml file to see the deployment. See the chart above for the image name and configuration required.

Add to faasd

Edit /var/lib/faasd/docker-compose.yaml and add:

  cron-connector:
    image: "ghcr.io/openfaas/cron-connector:latest"
    environment:
      - gateway_url=http://gateway:8080
      - basic_auth=true
      - secret_mount_path=/run/secrets
    volumes:
      # we assume cwd == /var/lib/faasd
      - type: bind
        source: ./secrets/basic-auth-password
        target: /run/secrets/basic-auth-password
      - type: bind
        source: ./secrets/basic-auth-user
        target: /run/secrets/basic-auth-user
    cap_add:
      - CAP_NET_RAW
    depends_on:
      - gateway

Then restart faasd.

Trigger a function from Cron

The function should have 2 annotations:

1. topic annotation should be cron-function.
2. schedule annotation should be the cron schedule on which to invoke function

For example, we may have a function "nodeinfo" which we want to invoke every 5 minutes:

Deploy via the CLI:

faas-cli store deploy nodeinfo --annotation schedule="*/5 * * * *" --annotation topic=cron-function

Or via stack.yml:

functions:
  nodeinfo:
    image: functions/nodeinfo
    annotations:
      topic: cron-function
      schedule: "*/5 * * * *"

You can learn how to create and test the Cron syntax here.