cron source Cron Source

Provided by: "Apache Software Foundation"

Support Level for this Kamelet is: "Preview"

Send events at specific time.

Configuration Options

The following table summarizes the configuration options available for the cron-source Kamelet:

Property Name Description Type Default Example

message *

Message

The message to generate

string

"hello world"

schedule *

Cron Schedule

A cron expression that will be used to trigger events generation.

string

"0/3 10 * * * ?"

Fields marked with (*) are mandatory.

Usage

This section summarizes how the cron-source can be used in various contexts.

Knative Source

The cron-source Kamelet can be used as Knative source by binding it to a Knative object.

cron-source-binding.yaml
apiVersion: camel.apache.org/v1alpha1
kind: KameletBinding
metadata:
  name: cron-source-binding
spec:
  source:
    ref:
      kind: Kamelet
      apiVersion: camel.apache.org/v1alpha1
      name: cron-source
    properties:
      message: "hello world"
      schedule: "0/3 10 * * * ?"
  sink:
    ref:
      kind: InMemoryChannel
      apiVersion: messaging.knative.dev/v1
      name: mychannel

Make sure you have Camel K installed into the Kubernetes cluster you’re connected to.

Save the cron-source-binding.yaml file into your hard drive, then configure it according to your needs.

You can run the source using the following command:

kubectl apply -f cron-source-binding.yaml

Binding to Knative using the Kamel CLI:

The procedure described above can be simplified into a single execution of the kamel bind command:

kamel bind cron-source -p "source.message=hello world" -p "source.schedule=0/3 10 * * * ?" channel/mychannel

This will create the KameletBinding under the hood and apply it to the current namespace in the cluster.

Kafka Source

The cron-source Kamelet can be used as Kafka source by binding it to a Kafka topic.

cron-source-binding.yaml
apiVersion: camel.apache.org/v1alpha1
kind: KameletBinding
metadata:
  name: cron-source-binding
spec:
  source:
    ref:
      kind: Kamelet
      apiVersion: camel.apache.org/v1alpha1
      name: cron-source
    properties:
      message: "hello world"
      schedule: "0/3 10 * * * ?"
  sink:
    ref:
      kind: KafkaTopic
      apiVersion: kafka.strimzi.io/v1beta1
      name: my-topic

Ensure that you’ve installed Strimzi and created a topic named my-topic in the current namespace. Make also sure you have Camel K installed into the Kubernetes cluster you’re connected to.

Save the cron-source-binding.yaml file into your hard drive, then configure it according to your needs.

You can run the source using the following command:

kubectl apply -f cron-source-binding.yaml

Binding to Kafka using the Kamel CLI:

The procedure described above can be simplified into a single execution of the kamel bind command:

kamel bind cron-source -p "source.message=hello world" -p "source.schedule=0/3 10 * * * ?" kafka.strimzi.io/v1beta1:KafkaTopic:my-topic

This will create the KameletBinding under the hood and apply it to the current namespace in the cluster.