Cron trigger

In this document

• Overview

• Attributes

• Examples

Overview

Triggers the function according to a schedule or interval, with an optional body.

Attributes

Path	Type	Description
schedule	string	A cron-like schedule (for example, */5 * * * *).
interval	string	An interval (for example, 1s, 30m).
concurrencyPolicy	string	Concurrency policy - "Allow", "Forbid", or "Replace"; (default: "Forbid"). Applicable only when using CronJobs on Kubernetes platforms (see the Kubernetes notes).
jobBackoffLimit	int32	The number of retries before failing a job; (default: 2). Applicable only when using CronJobs on Kubernetes platforms (see the Kubernetes notes).
event.body	string	The body passed in the event.
event.headers	map of string/int	The headers passed in the event.

Notes about configuring attributes

Note:

1. You must set either the schedule or interval mutually-exclusive attributes.

2. The event.* attributes are optional.

Kubernetes features

[Tech Preview] On Kubernetes platforms, you can set the cronTriggerCreationMode platform-configuration field to "kube" to run the triggers as Kubernetes CronJobs instead of the default implementation of running Cron triggers from the Nuclio processor. For more information, see Configuring a Platform. When running Cron triggers as CronJobs —

• The created CronJob uses wget to call the default HTTP trigger of the function according to the configured interval or schedule. (This means that worker-related attributes are irrelevant.)

  • The wget request is sent with the header "x-nuclio-invoke-trigger: cron".

  • You can use the concurrencyPolicy and jobBackoffLimit attributes to configure the CronJobs.

Examples

triggers:
  myCronTrigger:
    kind: cron
    attributes:
      interval: 3s

The following example is demonstrates a configuration for running Cron triggers as Kubernetes CronJobs, as it sets the concurrencyPolicy and jobBackoffLimit attributes. Remember that this implementation requires setting the cronTriggerCreationMode platform-configuration field to "kube". See the Kubernetes notes.

triggers:
  myCronTrigger:
    kind: cron
    attributes:
      interval: 10s
      concurrencyPolicy: "Allow"
      jobBackoffLimit: 2