Using a Single App Router for Multiple CAP Services

[BrianBacarezza]

Hello experts,

I hope you are all doing well.

I am currently working on a project where I need to configure a single App Router to handle multiple CAP (Cloud Application Programming) services. While I have successfully managed to use a single App Router for multiple SAPUI5 front-end applications, I am struggling to extend this approach to multiple CAP services.

Despite my research and experimentation, I have not yet found a clear or effective way to achieve this. I would greatly appreciate any guidance, recommendations, or best practices you might have on this matter.

Has anyone here managed to configure an App Router to seamlessly route requests to different CAP services within the same deployment? If so, I would be grateful for any insights or examples you could share.

Many thanks in advance for your help!

[Willem_Pardaens]

Hi Brian,

This should be perfectly possible since the approuter and the CAP service application are 2 distinct applications in any case. So whether it's a single CAP service application or multiple shouldn't really matter.

The approuter is responsible of getting the user authenticated against the bound xsuaa service instance. Then it will route requests to the correct destination (CAP service application) based on the route. Note that these destinations are configured with 'no authentication', basically meaning that the token that the approuter gives it, should suffice to gain access to the CAP service. This implies that each CAP service should rely on the exact same xsuaa service instance, otherwise they won't accept the token.

You could rewire the default destinations to do token exchange as well, but if it's not a problem to use a single xsuaa service instance then this would be the easiest approach.

So just make sure that all applications (approuter + CAP services) are bound to the same xsuaa service instance and that your routes are configured to forward the token (default setting).

If you experience any issues, it would help to post your MTA here, or provide a git with your sample code to explore further.