spring-gateway.md

Configure Spring Cloud Gateway Server

Spring Cloud Gateway aims to provide a simple, yet effective way to route to APIs and provide cross cutting concerns to them such as: security, monitoring/metrics, and resiliency.

Prerequisites

Before we begin, it’s recommended to have already completed Spring Config Server, Spring Config Client and Spring Discovery Server.

Maven Configuration

<dependency>
  <groupId>org.springframework.cloud</groupId>
  <artifactId>spring-cloud-starter-gateway</artifactId>
</dependency>

<dependency>
  <groupId>org.springframework.cloud</groupId>
  <artifactId>spring-cloud-starter-config</artifactId>
</dependency>

<dependency>
  <groupId>org.springframework.cloud</groupId>
  <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
</dependency>

Register with Config server

Configure spring.cloud.config.uri with config server url in bootstrap.yml.

spring:
  cloud:
    config:
      uri: ${config.url:http://localhost:8001}
      name: gateway

Register with Discovery Server

Add Spring Cloud’s @EnableDiscoveryClient to register the application to discovery server.

@SpringBootApplication
@EnableDiscoveryClient
public class SpringGatewayApplication {

    public static void main(String[] args) {
        SpringApplication.run(SpringGatewayApplication.class, args);
    }

}

Add discovery server url in the gateway-<profile>.yml file, available under config folder of config server.

• eureka.client.service.url.defaultZone = http://localhost:8101/eureka,http://localhost:8102/eureka.

Once the properties file of both nodes are updated, restart the config server.

Build the project

Execute mvn clean install to build the jar.

Test the Application

In order to test the application, we need to run below command

java -jar -Dspring.profiles.active=dev -Dserver.port=8003 spring-gateway-1.0.0.jar

Note: Start discovery nodes and config server before gateway server.

Once all the applications are running, we can test it by opening below url in browser.
Node 1 – http://localhost:8101/
Node 2 – http://localhost:8102/

You will notice that gateway server has registered itself on both eureka nodes.