EAM API: Support Callbacks for POST /appinstance

[travishepworth]

Problem description
The current mechanism for confirming whether an application successfully started after a POST /appinstances request relies on the status field in the response. This bundles the creation and launch phases into a single request, often returning a status of unknown or pending, which provides limited immediate insight.

Possible evolution
Introduce a callbackUrl field in the request body for POST /appinstances and send a callback to the endpoint after the application starts / fails to start utilizing the status enum already defined.

Alternative solution
Poll GET /appinstances until status is confirmed. However, this is less efficient and doesn’t support push-based workflows.

Additional context
A callback mechanism supports push-based automation, aligns with event-driven system design, and reduces client-side complexity for deployment monitoring.

[Kevsy]

Good point @travishepworth - can you look at the CAMARA notification guidelines here and see if they can be used here?

[jgarciatovar]

Thanks for the info @travishepworth and @Kevsy . I agree that this enhancement is part of the natural evolution of the API, and as Kevin pointed, CAMARA already defines guidelines to include it. We'll consider it in the next release of the API, including this and other possible enhancements soon.

[travishepworth]

Yes, I will take a look at the notification guidelines to see how it can be implemented into EAM