consul作为注册中心

consul提供的功能

• 支持多数据中心的服务注册，服务发现和服务配置
• 基于raft试下一致性算法
• 使用gossip协议管理成员状态和广播消息
• 支持ACL访问控制

consul的特点

• 高效的raft一致性算法
• 支持多数据中心
• 监控检查
• http和DNS支持

多个注册中心的对比

consul服务的构成

• server(多机器部署，一般是基数位的机器，leader负责写入。同数据中心使用LAN，不同数据中心使用WAN)

consul运行

/usr/local/bin/consul agent -dev -ui=true -client 0.0.0.0 &

spring服务运行

maven配置

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <parent>
        <artifactId>kconsul</artifactId>
        <groupId>cn.beckbi</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>kconsul-server</artifactId>


    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-consul-discovery</artifactId>
        </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.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>

    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                </configuration>
            </plugin>
        </plugins>
    </build>


</project>

server端

@RestController
public class UserController {

    private ObjectMapper mapper = new ObjectMapper();


    @RequestMapping("/info")
    public String info()  throws JsonProcessingException {

        @Data
        class User {
            private String name;
            private int age;
        }
        User user = new User();
        user.setName("tom");
        user.setAge(21);
        return mapper.writeValueAsString(user);
    }
}
spring.application.name=consul-server
server.port=7301


spring.cloud.consul.host=localhost
spring.cloud.consul.port=8500
spring.cloud.consul.discovery.service-name=consul-server-producer

client 端

@Slf4j
@RestController
public class ApiController {


    @Autowired
    private RestTemplate restTemplate;

    @Autowired
    private LoadBalancerClient loadBalancerClient;

    @RequestMapping("/info")
    public String info() {
        ServiceInstance serviceInstance = loadBalancerClient.choose("consul-server-producer");
        log.info("url:"+serviceInstance.getUri());
        log.info("url:"+serviceInstance.getServiceId());

        return restTemplate.getForObject(
                serviceInstance.getUri().toString()+"/info", String.class
        );
    }
}
@Configuration
public class RestConfig {


    @Bean
    public RestTemplate getRestTemplate() {
        return new RestTemplate();
    }
}


spring.application.name=consul-client-consumer
server.port=7302

spring.cloud.consul.host=localhost
spring.cloud.consul.port=8500
spring.cloud.consul.discovery.service-name=consul-client-consumer