readme.md

Server side discovery stage

This is request stage that adds a routing header to the request, in order to redirect on routing stage to the correct internal server

What is a server-side service discovery pattern

pattern

Installation

Maven:

<dependency>
  <groupId>com.dexmatech.styx</groupId>
  <artifactId>server-side-discovery</artifactId>
  <version>VERSION</version>
</dependency>

Usage

The usage is simple, you add routes to your internal load balancers, the they will resolve the real services ips.

Imagine that you have three internal load balancers:

1. api1.service.dmz -> resolve ips for api v1
2. api2.service.dmz -> resolve ips for api v1
3. default.service.dmz -> resolve other ips

RequestPipelineStage stage = ServerSideDiscoveryStage
				.usingDefaults()
				.withHostRoutingRule("/api/v1/.*","api1.service.dmz")
				.withHostRoutingRule("/api/v2/.*","api2.service.dmz")
				.withDefaultHostRule("default.service.dmz")
				.build();

Then if a request enter to a pipeline with:

request : http://www.mydomain.com:8080/api/v1/users

This stage will add a custom http header to the request:

X-route-to: http://api1.service.dmz:8080/api/v1/users

Hiding internal api paths

Imagine you want have some paths that you want to hide, for example you have an internal api with

• /api/items (for public purposes)
• /api/users (for internal use)

This two calls are in the same microservice or internal api but you don't want to expose /api/users to the world.

Then add to a blacklist:

RequestPipelineStage stage = ServerSideDiscoveryStage
				.usingDefaults()
				.withBlackList(Arrays.asList("/api/users.*"))
				.withDefaultHostRule("default.service.dmz")
				.build();

All request to /api/users path will be aborted returning an 404 error