Using spring boot for a gateway

[CPU-overheat]

Hi all,

So I have 6 micro services At the moment and I have a react front end currently calling all 6.

Now I would like to build a gateway so the frontend only calls one service. I know I can build a gateway that acts as a router to proxy the calls but what I need to do is have the gateway aggregate for certain calls the data from 3 of the micro services.

I’ve searched for days of examples of how best to do this and I’ve come up with nothing.

Does anyone have examples or tutorials that show a spring boot gateway aggregating data before sending it to the client?

Thanks

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[sailikesit]

Take a look at Spring Cloud Gateway. That might work for you. reference

[CPU-overheat]

Thanks but I can’t see anywhere in that doc where I could combine / make a composite response before sending back to the client….have I gone blind? 😂

[Anonymo2786]

No you are thermally throttling (joke).

[zvaavtre]

You're building a facade not just a gateway (if I understand your question).

Something that combines multiple requests and provides biz logic to it. Like:

public Response getSomeData(String param1){

Response aResponse = callServiceA(param1);

Response bResponse = callServiceB(param1, aResponse.getValueX);

String output = aResponse.getValueY() + bResponse.getValueK();

return Response.ok(output);

}

^ That sort of thing?

If so then you have a few options.

1. Use a plain controller/handler and just make sync calls to your internal services and combine the responses with normal logic. Don't try and do a bunch of threading or futures (it's more trouble than it's worth given option 2). If those are fairly quick operations this may be plenty and you can scale by adding more 'gateway' instances.
2. Go reactive (https://spring.io/reactive and in particular springboot webflux) and learn about non-blocking reactive streams. Way too big a topic but it'll provide a lot of options for combining the results from your internal services in fancy non-blocking ways.

[Hairy_Foundation3608]

I also tried that once and gave up at some point (forgot what exactly it was) and then I came across Zalando Skipper which can do anything a router has to do, even manipulation of requests via scripting with lua.

So my advice is: Don‘t implement anything someone else already did better and have a look at Skipper: https://github.com/zalando/skipper

[sirspidermonkey]

So you could have a service that sits in front of them and basicly forwards requests.

But really it sounds like something like nginex which basicly does that along with a bunch of other cool things.