今天小编给大家分享一下分布式服务注册发现与统一配置管理Consul的方法的相关知识点，内容详细，逻辑清晰，相信大部分人都还太了解这方面的知识，所以分享这篇文章给大家参考一下，希望大家阅读完这篇文章后有所收获，下面我们一起来了解一下吧。
Consul 服务端配置使用
下载相应版本解压，并将可执行文件复制到/usr/local/consul目录下
创建一个service的配置文件
silence$ sudo mkdir /etc/consul.dsilence$ echo '{"service":{"name": "web", "tags": ["rails"], "port": 80}}' | sudo tee /etc/consul.d/web.json
启动代理
silence$ /usr/local/consul/consul agent -dev -node consul_01 -config-dir=/etc/consul.d/ -ui-dev 参数代表本地测试环境启动；-node 参数表示自定义集群名称；-config-drir 参数表示services的注册配置文件目录，即上面创建的文件夹-ui 启动自带的web-ui管理页面
集群成员查询方式
silence-pro:~ silence$ /usr/local/consul/consul membersHTTP协议数据查询
silence-pro:~ silence$ curl http://127.0.0.1:8500/v1/catalog/service/web[ { "ID": "ab1e3577-1b24-d254-f55e-9e8437956009", "Node": "consul_01", "Address": "127.0.0.1", "Datacenter": "dc1", "TaggedAddresses": { "lan": "127.0.0.1", "wan": "127.0.0.1" }, "NodeMeta": { "consul-network-segment": "" }, "ServiceID": "web", "ServiceName": "web", "ServiceTags": [ "rails"], "ServiceAddress": "", "ServicePort": 80, "ServiceEnableTagOverride": false, "CreateIndex": 6, "ModifyIndex": 6 }]silence-pro:~ silence$web-ui管理Consul Web UI
Consul的web-ui可以用来进行服务状态的查看，集群节点的检查，访问列表的控制以及KV存储系统的设置，相对于Eureka和ETCD，Consul的web-ui要好用的多。（Eureka和ETCD将在下一篇文章中简单介绍。）
KV存储的数据导入和导出
silence-pro:consul silence$ ./consul kv import @temp.jsonsilence-pro:consul silence$ ./consul kv export redis/temp.json文件内容格式如下，一般是管理页面配置后先导出保存文件，以后需要再导入该文件
[ { "key": "redis/config/password", "flags": 0, "value": "MTIzNDU2" }, { "key": "redis/config/username", "flags": 0, "value": "U2lsZW5jZQ==" }, { "key": "redis/zk/", "flags": 0, "value": "" }, { "key": "redis/zk/password", "flags": 0, "value": "NDU0NjU=" }, { "key": "redis/zk/username", "flags": 0, "value": "ZGZhZHNm" }]Consul的KV存储系统是一种类似zk的树形节点结构，用来存储相关key/value键值对信息的，我们可以使用KV存储系统来实现上面提到的配置中心，将统一的配置信息保存在KV存储系统里面，方便各个实例获取并使用同一配置。而且更改配置后各个服务可以自动拉取最新配置，不需要重启服务。
Consul Java 客户端使用
maven pom依赖增加，版本可自由更换
<dependency> <groupId>com.orbitz.consul</groupId> <artifactId>consul-client</artifactId> <version>0.12.3</version></dependency><dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-actuator</artifactId></dependency>Consul 基本工具类，根据需要相应扩展
package com.coocaa.consul.consul.demo;import com.google.common.base.Optional;import com.google.common.net.HostAndPort;import com.orbitz.consul.*;import com.orbitz.consul.model.agent.ImmutableRegCheck;import com.orbitz.consul.model.agent.ImmutableRegistration;import com.orbitz.consul.model.health.ServiceHealth;import java.net.MalformedURLException;import java.net.URI;import java.util.List;public class ConsulUtil { private static Consul consul = Consul.builder().withHostAndPort(HostAndPort.fromString("127.0.0.1:8500")).build(); public static void serviceRegister() { AgentClient agent = consul.agentClient(); try { agent.register(8080, URI.create("http://localhost:8080/health").toURL(), 3, "tomcat", "tomcatID", "dev"); } catch (MalformedURLException e) { e.printStackTrace(); } } public static void findHealthyService(String serviceName) { HealthClient healthClient = consul.healthClient(); List<ServiceHealth> serviceHealthList = healthClient.getHealthyServiceInstances(serviceName).getResponse(); serviceHealthList.forEach((response) -> { System.out.println(response); }); } public static void storeKV(String key, String value) { KeyValueClient kvClient = consul.keyValueClient(); kvClient.putValue(key, value); } public static String getKV(String key) { KeyValueClient kvClient = consul.keyValueClient(); Optional<String> value = kvClient.getValueAsString(key); if (value.isPresent()) { return value.get(); } return ""; } public static List<String> findRaftPeers() { StatusClient statusClient = consul.statusClient(); return statusClient.getPeers(); } public static String findRaftLeader() { StatusClient statusClient = consul.statusClient(); return statusClient.getLeader(); } public static void main(String[] args) { AgentClient agentClient = consul.agentClient(); agentClient.deregister("tomcatID"); }}通过上面的基本工具类可以实现服务的注册和KV数据的获取与存储功能
Consul集群搭建
三台主机Consul下载安装，我这里没有物理主机，所以通过三台虚拟机来实现。虚拟机IP分192.168.231.145，192.168.231.146，192.168.231.147
将145和146两台主机作为Server模式启动，147作为Client模式启动，Server和Client只是针对Consul集群来说的，跟服务没有任何关系！
Server模式启动145，节点名称设为n1，数据中心统一用dc1
[root@centos145 consul]# ./consul agent -server -bootstrap-expect 2 -data-dir /tmp/consul -node=n1 -bind=192.168.231.145 -datacenter=dc1bootstrap_expect = 2: A cluster with 2 servers will provide no failure tolerance. See https://www.consul.io/docs/internals/consensus.html#deployment-tablebootstrap_expect > 0: expecting 2 servers==> Starting Consul agent...==> Consul agent running! Version: 'v1.0.1' Node ID: '6cc74ff7-7026-cbaa-5451-61f02114cd25' Node name: 'n1' Datacenter: 'dc1' (Segment: '<all>') Server: true (Bootstrap: false) Client Addr: [127.0.0.1] (HTTP: 8500, HTTPS: -1, DNS: 8600) Cluster Addr: 192.168.231.145 (LAN: 8301, WAN: 8302) Encrypt: Gossip: false, TLS-Outgoing: false, TLS-Incoming: false==> Log data will now stream in as it occurs: 2017/12/06 23:26:21 [INFO] raft: Initial configuration (index=0): [] 2017/12/06 23:26:21 [INFO] serf: EventMemberJoin: n1.dc1 192.168.231.145 2017/12/06 23:26:21 [INFO] serf: EventMemberJoin: n1 192.168.231.145 2017/12/06 23:26:21 [INFO] agent: Started DNS server 127.0.0.1:8600 (udp) 2017/12/06 23:26:21 [INFO] raft: Node at 192.168.231.145:8300 [Follower] entering Follower state (Leader: "") 2017/12/06 23:26:21 [INFO] consul: Adding LAN server n1 (Addr: tcp/192.168.231.145:8300) (DC: dc1) 2017/12/06 23:26:21 [INFO] consul: Handled member-join event for server "n1.dc1" in area "wan" 2017/12/06 23:26:21 [INFO] agent: Started DNS server 127.0.0.1:8600 (tcp) 2017/12/06 23:26:21 [INFO] agent: Started HTTP server on 127.0.0.1:8500 (tcp) 2017/12/06 23:26:21 [INFO] agent: started state syncer 2017/12/06 23:26:28 [ERR] agent: failed to sync remote state: No cluster leader 2017/12/06 23:26:30 [WARN] raft: no known peers, aborting election 2017/12/06 23:26:49 [ERR] agent: Coordinate update error: No cluster leader 2017/12/06 23:26:54 [ERR] agent: failed to sync remote state: No cluster leader 2017/12/06 23:27:24 [ERR] agent: Coordinate update error: No cluster leader 2017/12/06 23:27:27 [ERR] agent: failed to sync remote state: No cluster leader 2017/12/06 23:27:56 [ERR] agent: Coordinate update error: No cluster leader 2017/12/06 23:28:02 [ERR] agent: failed to sync remote state: No cluster leader 2017/12/06 23:28:27 [ERR] agent: failed to sync remote state: No cluster leader 2017/12/06 23:28:33 [ERR] agent: Coordinate update error: No cluster leader目前只启动了145，所以还没有集群
Server模式启动146，节点名称用n2，并在n2上启用了web-ui管理页面功能
[root@centos146 consul]# ./consul agent -server -bootstrap-expect 2 -data-dir /tmp/consul -node=n2 -bind=192.168.231.146 -datacenter=dc1 -uibootstrap_expect = 2: A cluster with 2 servers will provide no failure tolerance. See https://www.consul.io/docs/internals/consensus.html#deployment-tablebootstrap_expect > 0: expecting 2 servers==> Starting Consul agent...==> Consul agent running! Version: 'v1.0.1' Node ID: 'eb083280-c403-668f-e193-60805c7c856a' Node name: 'n2' Datacenter: 'dc1' (Segment: '<all>') Server: true (Bootstrap: false) Client Addr: [127.0.0.1] (HTTP: 8500, HTTPS: -1, DNS: 8600) Cluster Addr: 192.168.231.146 (LAN: 8301, WAN: 8302) Encrypt: Gossip: false, TLS-Outgoing: false, TLS-Incoming: false==> Log data will now stream in as it occurs: 2017/12/06 23:28:30 [INFO] raft: Initial configuration (index=0): [] 2017/12/06 23:28:30 [INFO] serf: EventMemberJoin: n2.dc1 192.168.231.146 2017/12/06 23:28:31 [INFO] serf: EventMemberJoin: n2 192.168.231.146 2017/12/06 23:28:31 [INFO] raft: Node at 192.168.231.146:8300 [Follower] entering Follower state (Leader: "") 2017/12/06 23:28:31 [INFO] consul: Adding LAN server n2 (Addr: tcp/192.168.231.146:8300) (DC: dc1) 2017/12/06 23:28:31 [INFO] consul: Handled member-join event for server "n2.dc1" in area "wan" 2017/12/06 23:28:31 [INFO] agent: Started DNS server 127.0.0.1:8600 (tcp) 2017/12/06 23:28:31 [INFO] agent: Started DNS server 127.0.0.1:8600 (udp) 2017/12/06 23:28:31 [INFO] agent: Started HTTP server on 127.0.0.1:8500 (tcp) 2017/12/06 23:28:31 [INFO] agent: started state syncer 2017/12/06 23:28:38 [ERR] agent: failed to sync remote state: No cluster leader 2017/12/06 23:28:39 [WARN] raft: no known peers, aborting election 2017/12/06 23:28:57 [ERR] agent: Coordinate update error: No cluster leader 2017/12/06 23:29:11 [ERR] agent: failed to sync remote state: No cluster leader 2017/12/06 23:29:30 [ERR] agent: Coordinate update error: No cluster leader 2017/12/06 23:29:38 [ERR] agent: failed to sync remote state: No cluster leader 2017/12/06 23:29:57 [ERR] agent: Coordinate update error: No cluster leader同样没有集群发现，此时n1和n2都启动起来，但是互相并不知道集群的存在！
将n1节点加入n2
[silence@centos145 consul]$ ./consul join 192.168.231.146此时n1和n2都打印发现了集群的日志信息
这个时候n1和n2两个节点已经是一个集群里面的Server模式的节点了
Client模式启动147
[root@centos147 consul]# ./consul agent -data-dir /tmp/consul -node=n3 -bind=192.168.231.147 -datacenter=dc1==> Starting Consul agent...==> Consul agent running! Version: 'v1.0.1' Node ID: 'be7132c3-643e-e5a2-9c34-cad99063a30e' Node name: 'n3' Datacenter: 'dc1' (Segment: '') Server: false (Bootstrap: false) Client Addr: [127.0.0.1] (HTTP: 8500, HTTPS: -1, DNS: 8600) Cluster Addr: 192.168.231.147 (LAN: 8301, WAN: 8302) Encrypt: Gossip: false, TLS-Outgoing: false, TLS-Incoming: false==> Log data will now stream in as it occurs: 2017/12/06 23:36:46 [INFO] serf: EventMemberJoin: n3 192.168.231.147 2017/12/06 23:36:46 [INFO] agent: Started DNS server 127.0.0.1:8600 (udp) 2017/12/06 23:36:46 [INFO] agent: Started DNS server 127.0.0.1:8600 (tcp) 2017/12/06 23:36:46 [INFO] agent: Started HTTP server on 127.0.0.1:8500 (tcp) 2017/12/06 23:36:46 [INFO] agent: started state syncer 2017/12/06 23:36:46 [WARN] manager: No servers available 2017/12/06 23:36:46 [ERR] agent: failed to sync remote state: No known Consul servers 2017/12/06 23:37:08 [WARN] manager: No servers available 2017/12/06 23:37:08 [ERR] agent: failed to sync remote state: No known Consul servers 2017/12/06 23:37:36 [WARN] manager: No servers available 2017/12/06 23:37:36 [ERR] agent: failed to sync remote state: No known Consul servers 2017/12/06 23:38:02 [WARN] manager: No servers available 2017/12/06 23:38:02 [ERR] agent: failed to sync remote state: No known Consul servers 2017/12/06 23:38:22 [WARN] manager: No servers available 2017/12/06 23:38:22 [ERR] agent: failed to sync remote state: No known Consul servers在n3上面将节点n3加入集群
[silence@centos147 consul]$ ./consul join 192.168.231.145再次查看集群节点信息
此时三个节点的Consul集群搭建成功了！其实n1和n2是Server模式启动，n3是Client模式启动。
关于Consul的Server模式和Client模式主要的区别是这样的，一个Consul集群通过启动的参数-bootstrap-expect来控制这个集群的Server节点个数，Server模式的节点会维护集群的状态，并且如果某个Server节点退出了集群，则会触发Leader重新选举机制，在会剩余的Server模式节点中重新选举一个Leader；而Client模式的节点的加入和退出很自由。
在n2中启动web-ui
以上就是“分布式服务注册发现与统一配置管理Consul的方法”这篇文章的所有内容，感谢各位的阅读！相信大家阅读完这篇文章都有很大的收获，小编每天都会为大家更新不同的知识，如果还想学习更多的知识，请关注编程网行业资讯频道。
