微服务-springcloud

感觉微服务都差不多概念，最近稍微看了下springcloud，感觉入门还是很简单的，框架用用就那么回事，深入的话需要很多时间投入了

学一个东西，我推荐首先从概念上了解到他是做什么的，什么时候需要，基本模块是什么，然后可以自己写一些小的例子，后续根据需要深入到探寻源码

某位热心同学写的入门例子，我下载学习了下：http://git.oschina.net/zhou666/spring-cloud-7simple

集成了了Netfix的一些关键组件：

服务发现——Netflix Eureka

客服端负载均衡——Netflix Ribbon

断路器——Netflix Hystrix

服务网关——Netflix Zuul

分布式配置——Spring Cloud Config

Eureka服务发现，启动后可以在控制台看到其他配置了该eureka地址的服务

application.properties中定义eureka服务相关信息

server.port=1111
eureka.instance.hostname=localhost
eureka.client.registerWithEureka=false
eureka.client.fetchRegistry=false
eureka.client.serviceUrl.defaultZone=http://${eureka.instance.hostname}:${server.port}/eureka/
spring.application.name=cloud-eureka-server
manager url:http://localhost:1111/

spring-boot 注解方式启动服务

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

打开控制台可以看到eureka服务已经启动成功

启动两个server2222/2223，在配置中制定eureka的服务地址

spring.application.name=ribbon-consumer
server.port=2222
eureka.client.serviceUrl.defaultZone=http://localhost:1111/eureka/

@EnableDiscoveryClient
@SpringBootApplication
public class ComputeServiceApplication {
    public static void main(String[] args) {
        new SpringApplicationBuilder(ComputeServiceApplication.class).web(true).run(args);
    }
}

启动后可以看到eureka控制台有这两个服务出现

修改端口为3333

启动ribbon轮询负载均衡器:

@SpringBootApplication
@EnableDiscoveryClient
public class RibbonApplication {
    @Bean
    @LoadBalanced
    RestTemplate restTemplate() {
        return new RestTemplate();
    }
    public static void main(String[] args) {
        SpringApplication.run(RibbonApplication.class, args);
    }
}

可以看到eureka可以发现该服务，并且访问http://localhost:3333/add?a=1&b=2时，后台分别传递给了2222和2223实现了负载均衡调度

Hystrix熔断机制：

application.yml

server:
  port: 8989

spring:
  application:
    name: turbine
  cloud:
    config:
      enabled: true
      uri: http://localhost:8888
eureka:
  instance:
    leaseRenewalIntervalInSeconds: 10
  client:
    registerWithEureka: true
    fetchRegistry: true
    serviceUrl:
      defaultZone: http://localhost:1111/eureka/

turbine:
  aggregator:
    clusterConfig: CLOUD-SIMPLE-UI
  appConfig: cloud-simple-ui
  clusterNameExpression: metadata['cluster']

@SpringBootApplication
@EnableEurekaClient
@EnableHystrixDashboard
@EnableTurbine
public class TurbineApplication {

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

Config配置管理:

server.port=8888
spring.cloud.config.server.git.uri=https://git.oschina.net/zhou666/spring-cloud-7simple.git
spring.cloud.config.server.git.searchPaths=cloud-config-repo
eureka.client.serviceUrl.defaultZone=http\://localhost\:1111/eureka/
spring.application.name=cloud-config-server

@Configuration
@EnableAutoConfiguration
@EnableDiscoveryClient
@EnableConfigServer
public class ConfigServerApplication {
    public static void main(String[] args) {
        SpringApplication.run(ConfigServerApplication.class, args);
    }
}

zuul服务网关，类似Nginx反向代理服务器，配置各种Ip过来给哪个下级处理

logging:
  level.org.springframework.cloud: DEBUG
server:
  port: 8080
zuul:
  ignoredPatterns: /health,/error
  retryable: true
  routes:
    smarts:
      stripPrefix: true
      path: /smart/**
      serviceId: smarts
ribbon:
  eureka:
    enabled: false
smarts:
  ribbon:
    listOfServers: localhost:2222,localhost:2223

定义映射规则，当访问http://localhost:8080/smart/add?a=1&b=2会按照规则/smart/**将请求定位到2222/2223

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