Create Event on SAP Event Mesh using CAP Application when Event Mesh instance is on different Space

In this example, Our goal is to create events on SAP Event Mesh through CAP App using Event Mesh Destination.

We will be following below steps-

1. Create Instance of Event Mesh on any Cloud Foundry Space
2. Create Queue and Subscription on Event Mesh
3. Create Event Mesh Destination on Subaccount
4. Create CAP App
5. Add destination configuration on package.json file
6. Define services of the app on srvice.cds file
7. Define services custom logic on srvice.js file
8. Add Hana, mta file, xsuaa and approuter file
9. Check the Destination binding mta.yaml file

Step 1 - Create Instance of Event Mesh on any Cloud Foundry Space

On SAP BTP Cockpit, go to the cloud foundry space on which you wants to create Event Mesh Instance.

For our application, we are creating Event Mesh instance - pocem

We are using emname - pocem and similar for namespace - pocem

while creating the Event mesh instance, we have used below json -

Step 2 - Create Queue and Subscription on Event Mesh

You can follow the similar way like we created for our application -

Step 3 - Create Event Mesh Destination on Subaccount

You can create service key on event mesh instance and use its credentials while creating the Destination.

You can refer below details -

Destination Name :- Any Name (in our case, we are using - EVENT_MESH_DEST_POC13App)

Type :- HTTP

URL :- uri from event mesh instance service key + /messagingrest/v1/topics/ + topic name

remember - replace / with %2f on topic name

since our topic was - companyName/subaccountName/pocem/cap/topic

after replacing / with %2f - companyName%2fsubaccountName%2fpocem%2fcap%2ftopic

Authtication :- OAuth2ClientCredentials

Proxy Type :- Internet

client Id :- client id from uaa section of event mesh instance service key

client secret :- client secret from uaa section of event mesh instance service key

token service url :- url from uaa section of event mesh instance service key + /oauth/token

Step 4 - Create CAP App

Follow below commands to create CAP app -

These dependencies are needed to consume Destination on CAP App.

In our case, the app name is poc13app

Step 5 - Add destination configuration on package.json file

In package.json file, add the below destination configuration after script or private key to connect connect with destination.

In our case package.json file looks like below -

Step 6 - Define services of the app on srvice.cds file

In your srv folder, create service.cds file and define the event and action on the serivce like below-

Step 7 - Define services custom logic on srvice.js file

In your srv folder, create service.file file and define the custom logic like below-

Step 8 - Add Hana, mta file, xsuaa and approuter file

use the below command for the same -

Step 9 - Check the Destination binding mta.yaml file

Make sure the Destination service binding is defined properly on mta.yaml file under resources section to create proper binding like below -

And the same is defined under modules requires on mta.yaml file -

Note - We are using name pocem because our event mesh instance has the name pocem

In our case, mta.yaml file looks like below -

And it is done, you can deploy your app and test it. !!!