Cron binding spec

Cron binding spec

Detailed documentation on the cron binding component

Component format

To setup cron binding create a component of type bindings.cron. See this guide on how to create and apply a binding configuration.

apiVersion: dapr.io/v1alpha1
kind: Component
metadata:
  name: <NAME>
spec:
  type: bindings.cron
  version: v1
  metadata:
  - name: schedule
    value: "@every 15m" # valid cron schedule

Spec metadata fields

Field	Required	Binding support	Details	Example
schedule	Y	Input	The valid cron schedule to use. See this for more details	`“@every 15m”`

Schedule Format

The Dapr cron binding supports following formats:

Character	Descriptor	Acceptable values
1	Second	0 to 59, or
2	Minute	0 to 59, or
3	Hour	0 to 23, or (UTC)
4	Day of the month	1 to 31, or
5	Month	1 to 12, or
6	Day of the week	0 to 7 (where 0 and 7 represent Sunday), or

For example:

30 * * * * * - every 30 seconds
0 15 * * * * - every 15 minutes
0 30 3-6,20-23 * * * - every hour on the half hour in the range 3-6am, 8-11pm
CRON_TZ=America/New_York 0 30 04 * * * - every day at 4:30am New York time

You can learn more about cron and the supported formats here

For ease of use, the Dapr cron binding also supports few shortcuts:

@every 15s where s is seconds, m minutes, and h hours
@daily or @hourly which runs at that period from the time the binding is initialized

Listen to the cron binding

After setting up the cron binding, all you need to do is listen on an endpoint that matches the name of your component. Assume the [NAME] is scheduled. This will be made as a HTTP POST request. The below example shows how a simple Node.js Express application can receive calls on the /scheduled endpoint and write a message to the console.

app.post('/scheduled', async function(req, res){
    console.log("scheduled endpoint called", req.body)
    res.status(200).send()
});

When running this code, note that the /scheduled endpoint is called every five minutes by the Dapr sidecar.

Binding support

This component supports input binding interface.

Last modified December 7, 2022: update cron docs (cd7055c8)