SpringCloud笔记04 Consul服务治理
coconutnut
 2020-04-20 11:06:19      

https://www.consul.io/

安装

https://learn.hashicorp.com/consul/getting-started/install.html

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% brew install consul
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% consul version
Consul v1.6.3
Protocol 2 spoken by default, understands 2 to 3 (agent will automatically use protocol >2 when speaking to compatible agents)

官方教程

https://learn.hashicorp.com/consul/getting-started/agent

启动服务器

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$ consul agent -dev

查看节点

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$ consul members

尝试

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% consul members
Node                  Address         Status  Type    Build  Protocol  DC   Segment
Ss-MacBook-Pro.local  127.0.0.1:8301  alive   server  1.6.3  2         dc1  <all>
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coconutnut@Ss-MacBook-Pro ~ % consul members -detailed
Node                  Address         Status  Tags
Ss-MacBook-Pro.local  127.0.0.1:8301  alive   acls=0,build=1.6.3:7f3b5f3+,dc=dc1,id=d9c5a17b-cc6b-1ca6-7c72-07304fbcccdc,port=8300,raft_vsn=3,role=consul,segment=<all>,vsn=2,vsn_max=3,vsn_min=2,wan_join_port=8302

但是member命令获取的信息只是eventually consistent的

一致性更强的方式是使用http api

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curl localhost:8500/v1/catalog/nodes

尝试

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% curl localhost:8500/v1/catalog/nodes
[
    {
        "ID": "d9c5a17b-cc6b-1ca6-7c72-07304fbcccdc",
        "Node": "Ss-MacBook-Pro.local",
        "Address": "127.0.0.1",
        "Datacenter": "dc1",
        "TaggedAddresses": {
            "lan": "127.0.0.1",
            "wan": "127.0.0.1"
        },
        "Meta": {
            "consul-network-segment": ""
        },
        "CreateIndex": 10,
        "ModifyIndex": 11
    }
]

也可以用dns

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% dig @127.0.0.1 -p 8600 Judiths-MBP.node.consul

; <<>> DiG 9.10.6 <<>> @127.0.0.1 -p 8600 Judiths-MBP.node.consul
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 33684
;; flags: qr aa rd; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1
;; WARNING: recursion requested but not available

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;Judiths-MBP.node.consul.	IN	A

;; AUTHORITY SECTION:
consul.			0	IN	SOA	ns.consul. hostmaster.consul. 1587353730 3600 600 86400 0

;; Query time: 0 msec
;; SERVER: 127.0.0.1#8600(127.0.0.1)
;; WHEN: Mon Apr 20 11:35:30 CST 2020
;; MSG SIZE  rcvd: 102

优雅的关闭节点

ctrl+C 暂停服务器

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$ consul leave

注册到consul

https://juejin.im/post/5db05582f265da4d4c20180f

将以前注册到eureka的服务改到consul

user-service模块

修改依赖

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<!--        <dependency>-->
<!--            <groupId>org.springframework.cloud</groupId>-->
<!--            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>-->
<!--        </dependency>-->

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

修改配置

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#eureka:
#  client:
#    register-with-eureka: true
#    fetch-registry: true
#    service-url:
#      defaultZone: http://localhost:8001/eureka/

cloud:
  consul:
    host: localhost
    port: 8500
    discovery:
      service-name: ${spring.application.name}

ribbon-service模块也是

Service Checks是X，但是可以访问？

但是http://localhost:8301/user/1获取不了

报错信息

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java.lang.IllegalStateException: No instances available for user-service

https://blog.csdn.net/kxj19980524/article/details/86935415

还需要加一个监控中心的依赖

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<dependency>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-actuator</artifactId>
</dependency>

重启

访问http://localhost:8301/user/1四次

控制台输出

交替调用

成功

总结

终端启动consul服务器

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$ consul agent -dev

Idea模块 consul客户端

依赖

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

<dependency>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-actuator</artifactId>
</dependency>

配置

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cloud:
  consul:
    host: localhost
    port: 8500
    discovery:
      service-name: ${spring.application.name}