Spring Cloud之微服务注册中心Consul
一、Consul概述
Consul是HashiCorp公司推出的开源产品，用于实现分布式系统的服务发现、服务隔离、服务配置，这些功能中的每一个都可以根据需要单独使用，也可以同时使用所有功能。
与其它分布式服务注册与发现的方案相比，Consul的方案更“一站式”——内置了服务注册与发现框架、分布一致性协议实现、健康检查、Key/Value 存储、多数据中心方案，不再需要依赖其它工具。
安装及使用Consul
下载https://www.consul.io/downloads
解压consul压缩包，并进入consul所在目录
cmd下执行如下命令：
1.开发者模式，数据存放内存中
consul agent -dev
2.服务模式，可以保留操作数据
consul agent -server -ui -bootstrap -data-dir D:\Development\consul\data -node=node1 -bind=127.0.0.1
agent: 启动Agent进程
server：启动server模式
bootstrap：节点是server-Leader ，每个数据中心只能运行一台服务器
ui：启动Web UI管理器，默认开放端口8500
node：节点的名称，集群中必须是唯一的，默认是该节点的主机名
data-dir: 数据存放路径
bind：consul服务侦听地址
D:\Development\consul>consul agent -server -ui -bootstrap -data-dir D:\Development\consul\data -node=node1 -bind=127.0.0.1
==> Starting Consul agent...
Version: '1.10.3'
Node ID: '0907bff1-3c02-59a5-dd91-1af0b8544984'
Node name: 'node1'
Datacenter: 'dc1' (Segment: '<all>')
Server: true (Bootstrap: true)
Client Addr: [127.0.0.1] (HTTP: 8500, HTTPS: -1, gRPC: -1, DNS: 8600)
Cluster Addr: 127.0.0.1 (LAN: 8301, WAN: 8302)
Encrypt: Gossip: false, TLS-Outgoing: false, TLS-Incoming: false, Auto-Encrypt-TLS: false
==> Log data will now stream in as it occurs:
T13:58:06.545+0800 [WARN] agent: BootstrapExpect is set to 1; this is the same as Bootstrap mode.
T13:58:06.593+0800 [WARN] agent: bootstrap = true: do not enable unless necessary
T13:58:07.007+0800 [WARN] agent.auto_config: BootstrapExpect is set to 1; this is the same as Bootstrap mode.
T13:58:07.007+0800 [WARN] agent.auto_config: bootstrap = true: do not enable unless necessary
T13:58:07.035+0800 [INFO] agent.server.raft: initial configuration: index=1 servers="[{Suffrage:Voter ID:0907bff1-3c02-59a5-dd91-1af0b8544984 Address:127.0.0.1:8300}]"
T13:58:07.035+0800 [INFO] agent.server.raft: entering follower state: follower="Node at 127.0.0.1:8300 [Follower]" leader=
T13:58:07.040+0800 [INFO] agent.server.serf.wan: serf: EventMemberJoin: node1.dc1 127.0.0.1
T13:58:07.043+0800 [INFO] agent.server.serf.lan: serf: EventMemberJoin: node1 127.0.0.1
T13:58:07.043+0800 [INFO] agent.router: Initializing LAN area manager
T13:58:07.044+0800 [INFO] agent.server: Adding LAN server: server="node1 (Addr: tcp/127.0.0.1:8300) (DC: dc1)"
T13:58:07.044+0800 [WARN] agent: grpc: addrConn.createTransport failed to connect to {dc1-127.0.0.1:8300 0 node1 <nil>}. Err :connection error: desc = "transport: Error while dialing dial tcp 127.0.0.1:0->127.0.0.1:8300: operation was canceled". Reconnecting...
T13:58:07.044+0800 [INFO] agent.server: Handled event for server in area: event=member-join server=node1.dc1 area=wan
T13:58:07.044+0800 [WARN] agent: grpc: addrConn.createTransport failed to connect to {dc1-127.0.0.1:8300 0 node1.dc1 <nil>}. Err :connection error: desc = "transport: Error while dialing dial tcp 127.0.0.1:0->127.0.0.1:8300: operation was canceled". Reconnecting...
T13:58:07.046+0800 [INFO] agent: Started DNS server: address=127.0.0.1:8600 network=udp
T13:58:07.046+0800 [INFO] agent: Started DNS server: address=127.0.0.1:8600 network=tcp
T13:58:07.049+0800 [INFO] agent: Starting server: address=127.0.0.1:8500 network=tcp protocol=http
T13:58:07.050+0800 [WARN] agent: DEPRECATED Backwards compatibility with pre-1.9 metrics enabled. These metrics will be removed in a future version of Consul. Set `telemetry { disable_compat_1.9 = true }` to disable them.
T13:58:07.050+0800 [INFO] agent: started state syncer
T13:58:07.050+0800 [INFO] agent: Consul agent running!
浏览器访问： http://localhost:8500
二、SpringCloud集成Consul
A、服务生产者
添加依赖
<!--健康检查依赖-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-consul-discovery</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-openfeign</artifactId>
</dependency>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>Hoxton.SR8</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
配置application.properties
server.port=8888
spring.application.name=consul-test
spring.cloud.consul.host=127.0.0.1
spring.cloud.consul.port=8500
spring.cloud.consul.discovery.service-name=${spring.application.name}
提供服务
@RestController
public class TestController {
@GetMapping("/test")
public String test() {
return "test success";
}
}
启动测试
启动Application，查看Consul的UI控制台界面
设置JVM参数：-DSERVER.PORT=9999，再启动一个实例
B、消费服务者
集成Feign：创建FeignClient项目,用于调用服务
添加依赖坐标
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-consul-discovery</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-openfeign</artifactId>
</dependency>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>Hoxton.SR8</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
创建调用接口
创建ConsulFeignClientTest接口
//指定调用的服务名称
@FeignClient("consul-test")
public interface ConsulFeignClientTest {
@GetMapping("/test")
public String test();
}
配置application.properties
server.port=7777
spring.application.name=fegin
spring.cloud.consul.host=127.0.0.1
spring.cloud.consul.port=8500
spring.cloud.consul.discovery.service-name=${spring.application.name}
spring.cloud.consul.discovery.register=false #不需要注册到consul,只需要去发现服务然后进行调用即可
开启FeignClient
启动类添加@EnableFeignClients注解
@SpringBootApplication
@EnableFeignClients
public class FeignAppliction {
public static void main(String[] args) {
SpringApplication.run(FeignAppliction.class,args);
}
}
测试
@Autowired
private ConsulFeignClientTest consulFeignClientTest;
@Test
public void test(){
String test = consulFeignClientTest.test();
System.out.println(test);
}
三、Consul配置中心支持
Consul不仅能用来服务注册和发现，还支持Key/Value键值对的存储，可以用来做配置中心，并且支持动态刷新，这样可以将工程中的配置信息保存在Cosul中。
添加依赖
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-consul-config</artifactId>
</dependency>
配置bootstrap.yml
新建配置文件bootstrap.yml ，bootstrap.yml优先application.yml加载
spring:
application:
name: consul
profiles:
active: dev
cloud:
consul:
host: 127.0.0.1
port: 8500
discovery:
serviceName: ${spring.application.name}
# 以下consul的config对应key值为：config/consul,dev/data
config:
enabled: true # 设置config是否启用，默认为true,从consul配置中心读取配置
format: yaml # 设置配置的值的格式，可以yaml和properties
prefix: config # 设置配的基本目录，如config,即key的前缀
defaultContext: consul # 设置默认的配置，被所有的应用读取,一般为应用名称
data-key: data
添加配置到Consul
将原来application.yml配置文件改名为application-dev.yml，并将该文件中的配置注释复制保存到
Consul中
key值为：config/consul,dev/data
内容为: application-dev.yml中的配置内容
注意: consul支持的K/V存储的Value值不能超过512KB
consul动态刷新
consul config作为配置中心时，是支持动态刷新的，动态刷新即当配置中心的配置发生改变，应用配置服务端能够动态及时的更新配置数据信息
@RestController
public class TestController {
@Value("${consul}")
private String consul;
@GetMapping("/test")
public String test() {
return consul;
}
}
在consul配置中心修改consul项的值
consul: 0.0.5
INFO 54344 --- [TaskScheduler-1] o.s.cloud.commons.util.InetUtils : Cannot determine local hostname
INFO 54344 --- [TaskScheduler-1] .e.DevToolsPropertyDefaultsPostProcessor : Devtools property defaults active! Set 'spring.devtools.add-properties' to 'false' to disable
INFO 54344 --- [TaskScheduler-1] o.s.cloud.commons.util.InetUtils : Cannot determine local hostname
INFO 54344 --- [TaskScheduler-1] .e.DevToolsPropertyDefaultsPostProcessor : Devtools property defaults active! Set 'spring.devtools.add-properties' to 'false' to disable
INFO 54344 --- [TaskScheduler-1] b.c.PropertySourceBootstrapConfiguration : Located property source: [BootstrapPropertySource {name='bootstrapProperties-config/consul,dev/'}, BootstrapPropertySource {name='bootstrapProperties-config/consul/'}]
INFO 54344 --- [TaskScheduler-1] o.s.boot.SpringApplication : The following profiles are active: dev
INFO 54344 --- [TaskScheduler-1] o.s.boot.SpringApplication : Started application in 4.541 seconds (JVM running for 417.332)
INFO 54344 --- [TaskScheduler-1] o.s.c.e.event.RefreshEventListener : Refresh keys changed: [consul]
四、Consul配置参数概览
spring.application.name=consul-config
# 指定consul的地址
spring.cloud.consul.host = 127.0.0.1
# 指定consul的端口,默认8500
spring.cloud.consul.port = 8500
#指定服务的实例id（唯一）
spring.cloud.consul.discovery.instance-id=${spring.application.name}
# 指定consul服务的名称
spring.cloud.consul.discovery.service-name=consul-config
# 是否启用服务发现
spring.cloud.consul.discovery.enabled=true
# 是否启用服务注册
spring.cloud.consul.discovery.register=true
# 是否服务停止时取消注册
spring.cloud.consul.discovery.deregister=true
# 在注册时使用consul IP,而不是hostname
spring.cloud.consul.discovery.prefer-ip-address=true
# 健康检查url
spring.cloud.consul.discovery.health-check-url=http://localhost:8081/actuator/health
# 健康检查的频率, 默认 10 秒
spring.cloud.consul.discovery.health-check-interval=10s
# 健康检查失败多长时间后，取消注册
spring.cloud.consul.discovery.health-check-critical-timeout=5s
# 启用配置中心
spring.cloud.consul.config.enabled=true
# 表示consul上面文件的格式 有四种 YAML PROPERTIES KEY-VALUE FILES
spring.cloud.consul.config.format=properties
#表示consul上面的KEY值(或者说文件的名字) 默认是data
spring.cloud.consul.config.data-key=data
#prefix设置配置值的基本文件夹
spring.cloud.consul.config.prefix=config
# 表示如果没有发现配置，是否抛出异常，true为是，false为否，当为false时，consul会打印warn级别的日志信息
spring.cloud.consul.config.fail-fast=false
#defaultContext设置所有应用程序使用的文件夹名称，指定consul配置的配置文件父路径
spring.cloud.consul.config.defaultContext=consul-config
#profileSeparator设置用于使用配置文件在属性源中分隔配置文件名称的分隔符的值
spring.cloud.consul.config.profileSeparator=,
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