From 77962dffc56a2f89afb4e53f917c9498d9c772c8 Mon Sep 17 00:00:00 2001
From: Spencer Gibb <spencer@gibb.us>
Date: Fri, 27 Jan 2017 17:08:51 -0700
Subject: [PATCH] Adds DiscoveryClientRouteReader

fixes gh-14
---
 pom.xml                                       | 12 +++++
 .../discovery/DiscoveryClientRouteReader.java | 51 +++++++++++++++++++
 .../gateway/test/GatewayTestApplication.java  | 22 ++++++++
 3 files changed, 85 insertions(+)
 create mode 100644 src/main/java/org/springframework/cloud/gateway/discovery/DiscoveryClientRouteReader.java

diff --git a/pom.xml b/pom.xml
index c8a8a254..ae929191 100644
--- a/pom.xml
+++ b/pom.xml
@@ -81,6 +81,18 @@
 			<groupId>org.springframework.boot</groupId>
 			<artifactId>spring-boot-devtools</artifactId>
 		</dependency>
+		<dependency>
+			<groupId>org.springframework.cloud</groupId>
+			<artifactId>spring-cloud-starter-eureka</artifactId>
+			<scope>test</scope>
+			<exclusions>
+				<exclusion>
+					<!-- TODO: this should be optional -->
+					<groupId>org.springframework.boot</groupId>
+					<artifactId>spring-boot-starter-web</artifactId>
+				</exclusion>
+			</exclusions>
+		</dependency>
 		<dependency>
 			<groupId>org.springframework.boot</groupId>
 			<artifactId>spring-boot-starter-test</artifactId>
diff --git a/src/main/java/org/springframework/cloud/gateway/discovery/DiscoveryClientRouteReader.java b/src/main/java/org/springframework/cloud/gateway/discovery/DiscoveryClientRouteReader.java
new file mode 100644
index 00000000..075526b2
--- /dev/null
+++ b/src/main/java/org/springframework/cloud/gateway/discovery/DiscoveryClientRouteReader.java
@@ -0,0 +1,51 @@
+package org.springframework.cloud.gateway.discovery;
+
+import org.springframework.cloud.client.discovery.DiscoveryClient;
+import org.springframework.cloud.gateway.api.RouteReader;
+import org.springframework.cloud.gateway.config.FilterDefinition;
+import org.springframework.cloud.gateway.config.PredicateDefinition;
+import org.springframework.cloud.gateway.config.Route;
+
+import reactor.core.publisher.Flux;
+
+import java.net.URI;
+
+/**
+ * @author Spencer Gibb
+ */
+public class DiscoveryClientRouteReader implements RouteReader {
+
+	private final DiscoveryClient discoveryClient;
+
+	public DiscoveryClientRouteReader(DiscoveryClient discoveryClient) {
+		this.discoveryClient = discoveryClient;
+	}
+
+	@Override
+	public Flux<Route> getRoutes() {
+		return Flux.fromIterable(discoveryClient.getServices())
+				.map(serviceId -> {
+					Route route = new Route();
+					route.setUri(URI.create("lb://" + serviceId));
+
+					// add a predicate that matches the url at /serviceId/**
+					PredicateDefinition predicate = new PredicateDefinition();
+					predicate.setName("Url");
+					predicate.setValue("/" + serviceId + "/**");
+					route.getPredicates().add(predicate);
+
+					//TODO: support for other default predicates
+
+					// add a filter that removes /serviceId by default
+					FilterDefinition filter = new FilterDefinition();
+					filter.setName("RewritePath");
+					filter.setValue("/" + serviceId + "/(?<remaining>.*)");
+					filter.setArgs(new String[]{ "/${remaining}" });
+					route.getFilters().add(filter);
+
+					//TODO: support for default filters
+
+					return route;
+				});
+	}
+}
diff --git a/src/test/java/org/springframework/cloud/gateway/test/GatewayTestApplication.java b/src/test/java/org/springframework/cloud/gateway/test/GatewayTestApplication.java
index 86017a18..680e0246 100644
--- a/src/test/java/org/springframework/cloud/gateway/test/GatewayTestApplication.java
+++ b/src/test/java/org/springframework/cloud/gateway/test/GatewayTestApplication.java
@@ -3,11 +3,33 @@ package org.springframework.cloud.gateway.test;
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.SpringBootConfiguration;
 import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.cloud.client.discovery.DiscoveryClient;
+import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
+import org.springframework.cloud.gateway.discovery.DiscoveryClientRouteReader;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Profile;
 
 @SpringBootConfiguration
 @EnableAutoConfiguration
 public class GatewayTestApplication {
 
+	/*
+	TO test run `spring cloud configserver eureka`,
+	then run this app with `--spring.profiles.active=discovery`
+	should be able to hit http://localhost:8008/configserver/foo/default a normal configserver api
+	 */
+	@Configuration
+	@EnableDiscoveryClient
+	@Profile("discovery")
+	protected static class GatewayDiscoveryConfiguration {
+
+		@Bean
+		public DiscoveryClientRouteReader discoveryClientRouteReader(DiscoveryClient discoveryClient) {
+			return new DiscoveryClientRouteReader(discoveryClient);
+		}
+	}
+
 	public static void main(String[] args) {
 		SpringApplication.run(GatewayTestApplication.class, args);
 	}