Spring Cloud Consul
Spring Cloud Consul项目是针对Consul的服务治理实现。Consul是一个分布式高可用的系统,它包含多个组件,但是作为一个整体,在微服务架构中为我们的基础设施提供服务发现和服务配置的工具。它包含了下面几个特性:
- 服务发现
- 健康检查
- Key/Value存储
- 多数据中心
由于Spring Cloud Consul项目的实现,我们可以轻松的将基于Spring Boot的微服务应用注册到Consul上,并通过此实现微服务架构中的服务治理。
以之前实现的基于Eureka的示例(eureka-client)为基础,我们如何将之前实现的服务提供者注册到Consul上呢?方法非常简单,我们只需要在pom.xml
中将eureka的依赖修改为如下依赖:
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<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-consul-discovery</artifactId>
</dependency>
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接下来再修改一下application.properites
,将consul需要的配置信息加入即可,比如:(下面配置是默认值)
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spring.cloud.consul.host=localhost
spring.cloud.consul.port=8500
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到此为止,我们将eureka-client转换为基于consul服务治理的服务提供者就完成了。前文我们已经有提到过服务发现的接口DiscoveryClient
是Spring Cloud对服务治理做的一层抽象,所以可以屏蔽Eureka和Consul服务治理的实现细节,我们的程序不需要做任何改变,只需要引入不同的服务治理依赖,并配置相关的配置属性就能轻松的将微服务纳入Spring Cloud的各个服务治理框架中。
下面可以尝试让consul的服务提供者运行起来。这里可能读者会问,不需要创建类似eureka-server的服务端吗?由于Consul自身提供了服务端,所以我们不需要像之前实现Eureka的时候创建服务注册中心,直接通过下载consul的服务端程序就可以使用。
我们可以用下面的命令启动consul的开发模式:
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$consul agent -dev
==> Starting Consul agent...
==> Starting Consul agent RPC...
==> Consul agent running!
Version: 'v0.7.2'
Node name: 'Lenovo-zhaiyc'
Datacenter: 'dc1'
Server: true (bootstrap: false)
Client Addr: 127.0.0.1 (HTTP: 8500, HTTPS: -1, DNS: 8600, RPC: 8400)
Cluster Addr: 127.0.0.1 (LAN: 8301, WAN: 8302)
Gossip encrypt: false, RPC-TLS: false, TLS-Incoming: false
Atlas: <disabled>
==> Log data will now stream in as it occurs:
2017/06/22 07:50:54 [INFO] raft: Initial configuration (index=1): [{Suffrage:Voter ID:127.0.0.1:8300 Address:127.0.0.1:8300}]
2017/06/22 07:50:54 [INFO] raft: Node at 127.0.0.1:8300 [Follower] entering Follower state (Leader: "")
2017/06/22 07:50:54 [INFO] serf: EventMemberJoin: Lenovo-zhaiyc 127.0.0.1
2017/06/22 07:50:54 [INFO] consul: Adding LAN server Lenovo-zhaiyc (Addr: tcp/127.0.0.1:8300) (DC: dc1)
2017/06/22 07:50:54 [INFO] serf: EventMemberJoin: Lenovo-zhaiyc.dc1 127.0.0.1
2017/06/22 07:50:54 [INFO] consul: Adding WAN server Lenovo-zhaiyc.dc1 (Addr: tcp/127.0.0.1:8300) (DC: dc1)
2017/06/22 07:51:01 [ERR] agent: failed to sync remote state: No cluster leader
2017/06/22 07:51:02 [WARN] raft: Heartbeat timeout from "" reached, starting election
2017/06/22 07:51:02 [INFO] raft: Node at 127.0.0.1:8300 [Candidate] entering Candidate state in term 2
2017/06/22 07:51:02 [DEBUG] raft: Votes needed: 1
2017/06/22 07:51:02 [DEBUG] raft: Vote granted from 127.0.0.1:8300 in term 2. Tally: 1
2017/06/22 07:51:02 [INFO] raft: Election won. Tally: 1
2017/06/22 07:51:02 [INFO] raft: Node at 127.0.0.1:8300 [Leader] entering Leader state
2017/06/22 07:51:02 [INFO] consul: cluster leadership acquired
2017/06/22 07:51:02 [INFO] consul: New leader elected: Lenovo-zhaiyc
2017/06/22 07:51:02 [DEBUG] consul: reset tombstone GC to index 3
2017/06/22 07:51:02 [INFO] consul: member 'Lenovo-zhaiyc' joined, marking health alive
2017/06/22 07:51:02 [INFO] agent: Synced service 'consul'
2017/06/22 07:51:02 [DEBUG] agent: Node info in sync
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consul服务端启动完成之后,我们再将之前改造后的consul服务提供者启动起来。consul与eureka一样,都提供了简单的ui界面来查看服务的注册情况:
从现在开始,我这边会将近期研发的springcloud微服务云架构的搭建过程和精髓记录下来,帮助更多有兴趣研发spring cloud框架的朋友,希望可以帮助更多的好学者。大家来一起探讨spring cloud架构的搭建过程及如何运用于企业项目。源码来源