Event Channels

Flexible event routing using Apache Camel Kamelets

Event Channels provide a flexible way to send CloudEvents to various target systems using Apache Camel Kamelets. Event Channels receive CloudEvents from NATS JetStream and deliver them to external destinations.

Configuration Format

Event channels are configured using YAML files:

apiVersion: weik.io/v1alpha1
kind: EventChannel
metadata:
  name: slack-notifications
  description: Send events to Slack channel
spec:
  type: slack
  parameters:
    webhookUrl: "{{slack_webhook}}"
    channel: "#notifications"
  variables:
    - slack_webhook: "{{sys:SLACK_WEBHOOK_URL}}"
  requirements:
    network: "true"

Applying Configuration

Use the Weikio CLI to apply event channel configurations:

weikio config apply filename.yaml

API Endpoints

1. GET /eventchannels/configurations

   • Returns all event channels
   • Requires “EventChannel.Read” policy

2. GET /eventchannels/configurations/{name}

   • Returns a specific event channel by name
   • Requires “EventChannel.Read” policy

Event Channel Types

Event channels are based on Apache Camel Kamelets. You can use any sink Kamelet from the Apache Camel Kamelet catalog.

Slack Channel

apiVersion: weik.io/v1alpha1
kind: EventChannel
metadata:
  name: slack-notifications
  description: Send events to Slack channel
spec:
  type: slack
  parameters:
    webhookUrl: "{{slack_webhook}}"
    channel: "#notifications"
  variables:
    - slack_webhook: "{{sys:SLACK_WEBHOOK_URL}}"
  requirements:
    network: "true"

AWS S3 Channel

apiVersion: weik.io/v1alpha1
kind: EventChannel
metadata:
  name: s3-archive
  description: Archive events to AWS S3 bucket
spec:
  type: aws-s3
  parameters:
    bucketNameOrArn: "events-archive"
    accessKey: "{{aws_access_key}}"
    secretKey: "{{aws_secret_key}}"
    region: "us-east-1"
    autoCreateBucket: "true"
  variables:
    - aws_access_key: "{{sys:AWS_ACCESS_KEY}}"
    - aws_secret_key: "{{sys:AWS_SECRET_KEY}}"
  requirements:
    network: "true"

HTTP Channel

apiVersion: weik.io/v1alpha1
kind: EventChannel
metadata:
  name: webhooksite-http
  description: Send events to Webhooksite
spec:
  type: http
  parameters:
    url: "{{target}}"
    method: "POST"
  variables:
    - target: "{{sys:webhooksite}}"

Event Processing

When an event channel is configured:

1. A NATS JetStream stream is automatically created

   • Stream name: eventchannel-{name}-stream
   • Subject: eventchannel.{name}
   • Republish configuration to eventchannelprocessing.{name}

2. An Integration Flow is created using the specified Kamelet

   • Flow reads CloudEvents from the NATS processing subject
   • CloudEvents are sent to the target system using the sink Kamelet

Integration with Other Features

Variables Support

Event channels can use variables in their configurations:

apiVersion: weik.io/v1alpha1
kind: EventChannel
metadata:
  name: s3-archive
spec:
  type: aws-s3
  parameters:
    bucketNameOrArn: "events-archive"
    accessKey: "{{aws_access_key}}"
    secretKey: "{{aws_secret_key}}"
  variables:
    - aws_access_key: "{{sys:AWS_ACCESS_KEY}}"
    - aws_secret_key: "{{sys:AWS_SECRET_KEY}}"

Requirements

Event channels support requirements specification:

apiVersion: weik.io/v1alpha1
kind: EventChannel
metadata:
  name: slack-notifications
spec:
  type: slack
  parameters:
    webhookUrl: "{{slack_webhook}}"
  variables:
    - slack_webhook: "{{sys:SLACK_WEBHOOK_URL}}"
  requirements:
    network: "true"