cloud-events

Cloud Events handling

Overview

This sample demonstrates how to subscribe Kyma Functions to the Cloud Events from SAP Event Mesh. It is based on the ce-coffee SAP FaaS Runtime example, and it's purpose is to show how to migrate similar use cases from deprecated SAP FaaS Runtime into Kyma runtime.

Additional prerequisites

Besides the prerequisites described in the parent folder, you must have access to an SAP BTP Event Mesh instance. Put the EMS instance data into the sap-ems.env file.

Steps

Inspect the Function files

Go to the cloud-events/ce-coffee folder and inspect the code (handler.js), dependencies (package.json) and the Function configuration file, which manifests the features of the Function (config.yaml) - in this case, the subscriptions to 3 types of Cloud Events.

NOTE: the eventType property must start with the sap.kyma.custom prefix and be followed by at least 4 comma-separated sections (7 in total).

Enable SAP EMS as Eventing backend

Create a Secret containing your EMS instance credentials.

kubectl create secret generic my-ems-instance --from-env-file=./sap-ems.env

Label the Secret so that Kyma Eventing can look it up and apply configuration.

kubectl label secret my-ems-instance kyma-project.io/eventing-backend=beb

NOTE: For more information on how to enable EMS eventing in Kyma runtime, see the following documentation.

Deploy the Function using Kyma CLI

NOTE: If you prefer to deploy the scenario using kubectl CLI, use the attached ce-coffee-resources.yaml with the kubectl apply command and skip to the testing part.

Run the following command to deploy the Function:

$ kyma apply function

To verify if the Function was built run:

$ kubectl get functions   
NAME              CONFIGURED   BUILT   RUNNING   RUNTIME    VERSION   AGE
ce-coffee         True         True    True      nodejs14   1         36s

To verify your subscription run:

$ kubectl get subscriptions
NAME        READY   AGE   CLEAN EVENT TYPES
ce-coffee   true    64s   ["sap.kyma.custom.commerce.coffee.required.v1","sap.kyma.custom.commerce.coffee.produced.v1","sap.kyma.custom.commerce.coffee.consumed.v1"]

Test the setup

• port forward eventing-publisher-proxy

kubectl port-forward -n kyma-system pod/$(kubectl get pod -n kyma-system -l app.kubernetes.io/name=eventing-publisher-proxy -ojsonpath="{.items[].metadata.name}") 8080:8080

• send Cloud Event message; make sure that the source and type have valid values

curl -v -X POST \
    -H "Content-Type: application/cloudevents+json" \
    --data '
    {
        "specversion": "1.0",
        "source": "/default/sap.kyma/faas-ems-test",
        "type": "sap.kyma.custom.commerce.coffee.required.v1",
        "eventtypeversion": "v1",
        "id": "A234-1234-1234",
        "data" : "{\"foo\":\"bar\"}",
        "datacontenttype":"application/json"
    }' http://localhost:8080/publish