Trigger a Microservice with an Event

1. Go to kyma-runtime-extension-samples.

2. Choose the Code button and choose one of the options to download the code locally, or simply run the following command using your CLI at your desired folder location:

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   git clone https://github.com/SAP-samples/kyma-runtime-extension-samples
   

1. Open the api-mssql-go directory in your local editor.

2. Explore the content of the sample.

   Within the internal/api/events.go file you can find the code that handles the consumption of the event data. This code expects to receive a JSON payload containing an orderCode. This function is exposed on the path /orderCodeEvent, which is defined in cmd/api/main.go.

   Within the k8s directory you can find the event.yaml file containing the event subscription definition which defines how an event will be consumed. The fields of interest include the following which would have to be altered if a different namespace or application name was used:

In this step, you will define an event subscription used to create an event subscriber. This allows you to specify that your api-mssql-go API application, by referencing its service, should receive the payload of the order.created event.

1. Apply the subscription by running the following command in the CLI:

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   kubectl -n dev apply -f ./k8s/event.yaml
   

2. Verify that the subscription was created successfully by running this command:

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   kubectl get subscription api-mssql-go-event-sub -n dev -o yaml
   

   After the event subscription definition, find a status object indicating the status of the related resources:

   yaml

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   status:
     conditions:
     - lastTransitionTime: "2021-05-06T14:54:50Z"
       reason: NATS Subscription active
       status: "True"
       type: Subscription active
     emsSubscriptionStatus: {}
     ready: true
   

With the configuration steps completed, you can now test the scenario to validate that it is working as intended.

1. Open the mock application in the browser by choosing Discovery and Network > API Rules from the menu.

2. Choose the Host entry for the commerce-mock APIRule to open it in the browser. This URL should be similar to:
   https://commerce-mock.*******.kyma.ondemand.com

3. Choose the Remote APIS tab.

   

4. Choose the SAP Commerce Cloud - Events option.

5. For the Event Topics, choose order.created.v1.

6. Modify the orderCode value as desired and choose Send Event.

   

7. In Kyma dashboard, choose Discovery and Network > API Rules from the menu.

8. Choose the Host entry for the fe-ui5-mssql APIRule to open the application in the browser. This should be similar to:
   https://fe-ui5-mssql.*******.kyma.ondemand.com

9. You should now see the data received by the event as shown below: