Creating a Subscription using Kyma Eventing

Set up a new namespace.

1. Create namespace eventing:

   

   

   

Create a new function using the Kyma Dashboard.

1. Select the namespace that you just set up.

2. Navigate to Workloads / Functions and select Create Function:

   

3. Insert the parameters as follows:

   

4. Choose Create.

5. On the dashboard you will receive, choose Edit as you want to replace the source of the function's editor:

   

6. In the Edit window, insert this code:

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   module.exports = { 
       main: async function (event, context) { 
       console.log("Received event:", event.data); 
       return; 
       } 
   } 

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7. Choose Update:

   

8. After some seconds, your function should be running, and it will look as follows:

   

Set up a subscription with various filters using the Kyma Dashboard.

1. Navigate to workloads / functions and select the menu Configuration. Here, choose Create Subscription.

   

2. Configure the subscription window with the following parameters (here you have to add another filter):

   • Name: lastorder-sub
   • Service: lastorder

   

3. For the filters, insert the following parameters.

   • Filter 1: sap.kyma.custom.myapp.order.received.v1
   • Filter 2: sap.kyma.custom.myapp.order.changed.v1
   

4. Choose Create.

5. After some seconds, your subscription is ready and will look as follows:

   

Trigger the workload with an event.

In this task, you will publish the events order.received.v1 and order.changed.v1 and trigger the function.

Note

For specifying the event payload, you can send events based on the CloudEvents specification. Various SDKs are also available, so that you could publish/emit and subscribe/consume them in your custom applications written in a variety of different programming languages.

1. Open a terminal window and run:

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   kubectl -n kyma-system port-forward service/eventing-event-publisher-proxy 3000:80

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2. Open another terminal window and run the following in order to publish the event order.received.v1 and trigger the function:

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   curl -v -X POST -H "ce-specversion: 1.0" -H "ce-type: sap.kyma.custom.myapp.order.received.v1" -H "ce-source: myapp" -H "ce-eventtypeversion: v1" -H "ce-id: cc99dcdd-6f6d-43d6-afef-d024eb276584" -H "content-type: application/json" -d "{\"orderCode\":\"3211213\", \"orderStatus\":\"received\"}" http://localhost:3000/publish

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3. In the same terminal window, run the following in order to publish the event order.changed.v1 and trigger the function:

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   curl -v -X POST -H "ce-specversion: 1.0" -H "ce-type: sap.kyma.custom.myapp.order.changed.v1" -H "ce-source: myapp -H "ce-eventtypeversion: v1" -H "ce-id: 94064655-7e9e-4795-97a3-81bfd497aac6" -H "content-type: application/json" -d "{\"orderCode\":\"3211213\", \"orderStatus\":\"changed\"}" http://localhost:3000/publish

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Confirm event delivery

1. On the Kyma Dashboard on the SAP BTP, navigate to Workloads / Functions. Choose your function lastorder:

   

2. Scroll down to the section Replicas of the Function and choose the name:

   

3. In the section Containers, choose View Logs:

   

4. If the events were delivered successfully, they will appear in the logs as follows: