I recently started a project that involves the development of a microservices architecture with Spring Cloud and Netflix OSS. The microservices are RESTful and produce JSON responses.
The goal is to compose the JSON results of each microservice (they may be dependencies among them, e.g. Service_B needs the output of Service_A in order to complete its computation) and present it to the end-user with a UI (i.e. Angular.js single page).
As a reference, I followed the guide of callista enterprise, in which the composition of three sample microservices (product, recommendation, review) is done by another microservice called "product-composite" that basically performs a sequence of http calls to the other microservices.
At this point I'm a little bit confused about this composition/orchestration approach since it does not scale and requires a substantial change each time a new microservice is added to the architecture.
The question is: what is the best/appropriate approach to compose/orchestrate microservices in a structured flow?
I looked for composing each service in a single Angular.js page but I'm concerned about exposing each microservice to the outside, since the desiderata is to call a single API endpoint (let's say /report) and obtain the whole computation required.
Another option seems Spring Integration but I cannot find documentation that clarifies how to map this kind of architecture with this technology.
Any tips, guides, references and suggestion will be really appreciated. Thanks for your support.
Luca
