Skip to content

Latest commit

 

History

History
130 lines (93 loc) · 3.63 KB

spring-rest.md

File metadata and controls

130 lines (93 loc) · 3.63 KB

Spring REST API - Sample Rest API

Simple rest application with /hello endpoint.This application will register with discovery server and will be behind Spring gateway.

Service Maven Configuration

<dependency>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-web</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: rest

Register with Discovery Server

Spring Cloud’s @EnableDiscoveryClient is used to register application to discovery server.

@SpringBootApplication
@EnableDiscoveryClient
public class SpringRestApplication {

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

Update rest-<profile>.yml file, available under config folder as defined in config server.

Above property holds the url(s) of discivery servers.

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

Register for Spring Cloud Bus

We will register this application to Spring Bus in order to have dynamic property update from config server.

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

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

We need to put @RefreshScope on the properties we want to update dynamically.

@Bean
@ConfigurationProperties(prefix = "rest")
@RefreshScope
public ApplicationProperties applicationProperties() {
  return new ApplicationProperties();
}

In the code above, all the properties defined in ApplicatioProperties file will be refreshed (if updated from config server)

Configure Gateway Service

In order for gateway server to send request to REST, we need to add the service to gateway server.

Navigate to gateway-<profile>.yml file and update it as below.

spring.application.name of registering app is used with lb

spring:
  cloud:
    gateway:
      routes:
      - id: hello-service
        uri: lb://REST
        predicates:
        - Path=/hello

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=8004 spring-rest-1.0.0.jar

Note: Start discovery nodes and config server before starting this 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 REST-SERVICE has registered itself on both eureka nodes.

To test the endpoint hit http://localhost:8003/hello. Notice that we are hitting 8003 port of gateway service and not the backend rest service directly.

Test Spring Cloud Bus

In order to test dynamic property update, perform below steps.

  • Update the property rest.greeting to a new value in rest-.yml file under config location.
  • Hit http://localhost:8003/hello again.
  • Latest updated value should be available in the response.