Consul概述

Consul是一套开源的分布式服务发现和配置管理系统，由HashiCorp公司用Go语言开发。

提供了微服务系统中的服务治理、配置中心、控制总线等功能。这些功能中的每一个都可以根据需要单独使用，也可以一起使用以构建全方位的服务网格,总之Consul提供了一种完整的服务网格解决方案。

它具有很多优点。包括:基于raft协议，比较简洁；支持健康检查，同时支持HTTP和DNS协议，支持跨数据中心的WAN集群，提供图形界面，跨平台，支持Linux、Mac、 Windows

下载地址： https://www.consul.io/downloads.html

使用

使用consul agent -dev开发模式启动，启动成功访问 http://localhost:8500/ 则有图形化管理界面

服务注册

新建cloud-providerconsul-payment8006模块，依赖：

<!--SpringCloud consul-server-->
<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-consul-discovery</artifactId>
</dependency>
<dependency>
    <groupId>com.rhett</groupId>
    <artifactId>cloud-api-common</artifactId>
    <version>${project.version}</version>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-devtools</artifactId>
    <scope>runtime</scope>
    <optional>true</optional>
</dependency>
<dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId>
    <optional>true</optional>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-test</artifactId>
    <scope>test</scope>
</dependency>

yaml配置：

server:
  port: 8006
spring:
  application:
    name: consul-provider-payment
# consul 注册中心地址
  cloud:
    consul:
      host: localhost
      port: 8500
      discovery:
        service-name: ${spring.application.name}

启动类：

@SpringBootApplication
@EnableDiscoveryClient
public class PaymentMain8006 {
    public static void main(String[] args) {
        SpringApplication.run(PaymentMain8006.class,args);
    }
}

controller:

@RestController
@Slf4j
public class PaymentController {
    @Value("${server.port}")
    private String serverPort;

    @RequestMapping(value = "/payment/consul")
    public String paymentConsul(){
        return "SpringCloud with Consul: "+serverPort+"\t"+ UUID.randomUUID().toString();
    }

}

运行该模块，即可看到服务被注册到consul上了

服务消费

新建cloud-consumerconsul-order80模块，依赖：

<!--SpringCloud consul-server-->
<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-consul-discovery</artifactId>
</dependency>
<dependency>
    <groupId>com.rhett</groupId>
    <artifactId>cloud-api-common</artifactId>
    <version>${project.version}</version>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>
<!--监控-->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<!--热部署-->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-devtools</artifactId>
    <scope>runtime</scope>
    <optional>true</optional>
</dependency>
<dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId>
    <optional>true</optional>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-test</artifactId>
    <scope>test</scope>
</dependency>

yaml配置，也注册到consul上

server:
  port: 80
spring:
  application:
    name: cloud-consumer-order
  # consul注册中心地址
  cloud:
    consul:
      host: localhost
      port: 8500
      discovery:
        service-name: ${spring.application.name}

获取RestTemplate的配置类：

@Configuration
public class ApplicationContextConfig {
    @Bean
    @LoadBalanced
    public RestTemplate getRestTemplate(){
        return new RestTemplate();
    }
}

启动类：

@SpringBootApplication
@EnableDiscoveryClient
public class OrderConsulMain80 {
    public static void main(String[] args) {
        SpringApplication.run(OrderConsulMain80.class, args);
    }

}

controller：

@RestController
@Slf4j
public class OrderConsulController {
    public static final String INVOKE_URL = "http://consul-provider-payment";

    @Resource
    private RestTemplate restTemplate;

    @GetMapping("/consumer/payment/consul")
    public String getPayment(){
        return restTemplate.getForObject(INVOKE_URL+"/payment/consul",String.class);
    }

}

保持consul运行，启动服务提供方和消费方，访问 http://localhost/consumer/payment/consul 就能看到结果了。