Consul 的安装与基本使用

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mb5fe18e9fef50b 2019-11-27 16:16:00

文章标签 java经验集锦通用实践 Spring SpringMVC springCloud 文章分类 代码人生

什么是 Consul
Consul是一种服务网格解决方案，提供具有服务发现，配置和分段功能的全功能控制平面。这些功能中的每一个都可以根据需要单独使用，也可以一起使用以构建全服务网格。Consul需要数据平面并支持代理和本机集成模型。Consul附带一个简单的内置代理，因此一切都可以开箱即用，但也支持第三方代理集成，如Envoy
Consul的主要特点

服务发现：Consul 的客户可以注册服务，例如 api或mysql，并且其他客户可以使用Consul来发现给定服务的提供者。使用 DNS 或 HTTP，应用程序可以轻松找到它们所依赖的服务。
运行状况检查：Consul 客户端可以提供任意数量的运行状况检查，这些检查与给定服务（“是 Web 服务器返回 200 OK”）或本地节点（“内存利用率低于 90％”）相关联。运营商可以使用此信息来监控群集运行状况，服务发现组件使用该信息将流量路由远离不健康的主机。
KV 商店：应用程序可以将 Consul 的分层键/值存储用于任何目的，包括动态配置，功能标记，协调，领导者选举等。简单的 HTTP API 使其易于使用。
安全服务通信：Consul可以为服务生成和分发 TLS 证书，以建立相互的 TLS 连接。意图可用于定义允许哪些服务进行通信。可以使用可以实时更改的意图轻松管理服务分段，而不是使用复杂的网络拓扑和静态防火墙规则。
多数据中心：Consul 支持多个数据中心。这意味着 Consul 的用户不必担心构建额外的抽象层以扩展到多个区域。

Consul 是一个分布式，高度可用的系统。本节将介绍基础知识，故意省略一些不必要的细节，以便您快速了解Consul的工作原理。有关更多详细信息，请参阅深入的体系结构概述

1、安装

通过官网地址下载对应的安装包
以 Linux 的为例，将安装包解压在任意喜欢的目录之中如: /usr/local

在 /usr/local 建立 consul 目录

将下载好的压缩包移动值该目录解压: unzip consul_1.4.4_linux_amd64.zip

为了方便起见，将得到的 consul 命令文件拷贝一份到 /usr/local/bin 目录之中即可全局使用

cp ./consul /usr/local/bin/

如若无误在任意位置输入: consul version 即可看到对应的 consul 的版本信息

Consul v1.4.4
Protocol 2 spoken by default, understands 2 to 3 (agent will automatically use protocol >2 when speaking to compatible agents)

2、启动

基本命令(前台启动)

consul agent -server -bind=192.168.xxx.134 -client=0.0.0.0 -bootstrap-expect=1 -data-dir=/usr/data/consul_data -node=server1

**-server ** 表示以服务端身份启动
**-bind ** 强制绑定到指定 IP
-client 指定客户端访问的 IP (consul 有丰富的 api 接口，这里的客户端指浏览器或调用方)，0.0.0.0 表示不限制客户端 IP
-bootstrap-expect=3 表示 server 集群最低节点为 3，低于这个值将工作不正常(注：类似zookeeper一样，通常集群数为奇数，方便选举，consul采用的是raft算法)
-data-dir 表示指定数据的存放目录(该目录必须已存在)
-node 表示节点在 web ui 中显示的名称

启动成功后，不要关闭终端窗口，在浏览器之中访问:http://192.168.xxx.134:8500/ ，如若无误将会得到:

Consul Agent

后台启动

nohup consul agent -server -bind=192.168.xxx.134 -client=0.0.0.0 -bootstrap-expect=1 -data-dir=/usr/data/consul_data -node=server1  > /dev/null 2>&1 &

3、启动 client 端

与 Server 端类似，去除掉 -server 即可

nohup consul agent -bind=192.168.xxx.134 -http-port=8500 -dns-port=8600 -client=0.0.0.0 -data-dir=/usr/data/consul_data/ -node=client1  > /dev/null 2>&1 &

指定 http 与 dns 端口号

nohup consul agent -bind=192.168.xxx.134 -http-port=7500 -dns-port=7600 -client=0.0.0.0 -data-dir=/usr/data/consul_data/ -node=client1  > /dev/null 2>&1 &

4、带 UI 启动

nohup consul agent -server -bind=192.168.xxx.134 -client=0.0.0.0 -bootstrap-expect=1 -data-dir=/usr/data/consul_data -node=server1 -ui > /dev/null 2>&1 &

5、搭建集群

搭建多个节点，在多个节点中启动 Consul ，通过 join 命令关联示例

例如: 将当前节点添加到 192.168.xxx.131 节点之中

consul join 192.168.xxx.131

成功后，会输出：Successfully joined cluster by contacting 1 node

查看集群：consul members

Node     Address               Status  Type    Build  Protocol  DC   Segment
server1  192.168.xxx.134:8301  alive   server  1.4.4  2         dc1  <all>
server2  192.168.xxx.131:8301  alive   server  1.4.4  2         dc1  <all>

6、服务注册/发现/注销

目前在 services 里，除了 consul 外，还没有其他服务，我们可以通过 service api 来进行注册，可以通过 postman、Insomnia 等 rest api工具或者 curl 命令，向服务注册地址进行注册，以 PUT 方式提交、Content-Type 为 application/json 格式，参数设置为以下 JSON 内容

{
     "ID": "elasticsearchID",
      "Service": "elasticsearch",
     "Name":"my-service-name",
      "Tags": [
                "mytags=1"
            ],
      "Meta": {
          "elasticsearch_version": "4.0"
      },
      "Port": 8080,
      "Address": "192.168.xxx.1",
      "EnableTagOverride": false,
      "Weights": {
          "Passing": 10,
          "Warning": 1
      }
}

往 192.168.xxx.131 这台机器的注册一个名为 my-service-name，ID 为 elasticsearchID的服务
具体 API 解释与更多使用参考官网

服务发现，查看已注册成功的服务
直接通过浏览器请求: http://192.168.xxx.131:8500/v1/agent/services 如若以上内容注册成功可获取到以下结果
{ "elasticsearchID": { "ID": "elasticsearchID", "Service": "my-service-name", "Tags": [ "mytags=1" ], "Meta": { "elasticsearch_version": "4.0" }, "Port": 8080, "Address": "192.168.xxx.1", "Weights": { "Passing": 10, "Warning": 1 }, "EnableTagOverride": false } }
服务注销
通过 PUT 请求方式，调用: http://192.168.xxx.131:8500/v1/agent/service/deregister/elasticsearchID
即注销了elasticsearchID 这个服务信息,可调用 http://192.168.xxx.131:8500/v1/agent/services 查看该服务是否已被注销

7、开发者模式

前面的几步操作在开发的过程中操作起来的步骤相对繁琐，因此 consul 也为开发人员推出了开发者模式(即 dev) 使用方式及其简单,输入如下命令即可:

consul agent -dev

开发模式，自带了 web ui，当然此种方式也默认 IP 为: 127.0.0.1 ，所以直接输入:http://127.0.0.1:8500 访问 UI 页面

8、在 Spring Cloud 中使用 Consul

创建一个 Spring Cloud 工程「microcloud」，在该工程中使用 Consul

创建「microcloud」，配置父 pom.xml 文件
<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.microcloud</groupId> <artifactId>microcloud</artifactId> <packaging>pom</packaging> <version>1.0-SNAPSHOT</version> <modules> <module>microcloud-consul-8501</module> </modules>
<name>microcloud</name>  <url>http://www.example.com</url>

<properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <maven.compiler.source>1.8</maven.compiler.source> <maven.compiler.target>1.8</maven.compiler.target> <jdk.version>1.8</jdk.version> </properties>

<dependencyManagement> <dependencies>  <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-dependencies</artifactId> <version>Greenwich.RELEASE</version> <type>pom</type> <scope>import</scope> </dependency>  <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-dependencies</artifactId> <version>2.1.4.RELEASE</version> <type>pom</type> <scope>import</scope> </dependency> </dependencies> </dependencyManagement>

<build> <finalName>microcloud</finalName> <plugins> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-compiler-plugin</artifactId> <configuration> <source>${jdk.version}</source>  <target>${jdk.version}</target> <encoding>${project.build.sourceEncoding}</encoding> </configuration> </plugin> </plugins>

<span ><!--资源文件打包管理--></span>
<span ><span ><span ><</span>resources</span><span >></span></span>
  <span ><span ><span ><</span>resource</span><span >></span></span>
    <span ><span ><span ><</span>directory</span><span >></span></span>src/main/resources<span ><span ><span ></</span>directory</span><span >></span></span>
    <span ><span ><span ><</span>includes</span><span >></span></span>
      <span ><span ><span ><</span>include</span><span >></span></span>**/*.properties<span ><span ><span ></</span>include</span><span >></span></span>
      <span ><span ><span ><</span>include</span><span >></span></span>**/*.yml<span ><span ><span ></</span>include</span><span >></span></span>
      <span ><span ><span ><</span>include</span><span >></span></span>**/*.xml<span ><span ><span ></</span>include</span><span >></span></span>
      <span ><span ><span ><</span>include</span><span >></span></span>**/*.tld<span ><span ><span ></</span>include</span><span >></span></span>
    <span ><span ><span ></</span>includes</span><span >></span></span>
    <span ><span ><span ><</span>filtering</span><span >></span></span>true<span ><span ><span ></</span>filtering</span><span >></span></span>
  <span ><span ><span ></</span>resource</span><span >></span></span>

  <span ><span ><span ><</span>resource</span><span >></span></span>
    <span ><span ><span ><</span>directory</span><span >></span></span>src/main/java<span ><span ><span ></</span>directory</span><span >></span></span>
    <span ><span ><span ><</span>includes</span><span >></span></span>
      <span ><span ><span ><</span>include</span><span >></span></span>**/*.properties<span ><span ><span ></</span>include</span><span >></span></span>
      <span ><span ><span ><</span>include</span><span >></span></span>**/*.yml<span ><span ><span ></</span>include</span><span >></span></span>
      <span ><span ><span ><</span>include</span><span >></span></span>**/*.xml<span ><span ><span ></</span>include</span><span >></span></span>
      <span ><span ><span ><</span>include</span><span >></span></span>**/*.tld<span ><span ><span ></</span>include</span><span >></span></span>
    <span ><span ><span ></</span>includes</span><span >></span></span>
    <span ><span ><span ><</span>filtering</span><span >></span></span>true<span ><span ><span ></</span>filtering</span><span >></span></span>
  <span ><span ><span ></</span>resource</span><span >></span></span>
<span ><span ><span ></</span>resources</span><span >></span></span>

</build> </project>
创建「microcloud-consul-8501」模块，配置 pom.xml 文件
<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <parent> <artifactId>microcloud</artifactId> <groupId>com.microcloud</groupId> <version>1.0-SNAPSHOT</version> </parent> <modelVersion>4.0.0</modelVersion> <artifactId>microcloud-consul-8501</artifactId> <name>microcloud-consul-8501</name> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-jetty</artifactId> </dependency>

<span ><span ><span ><</span>dependency</span><span >></span></span>
        <span ><span ><span ><</span>groupId</span><span >></span></span>org.springframework.boot<span ><span ><span ></</span>groupId</span><span >></span></span>
        <span ><span ><span ><</span>artifactId</span><span >></span></span>spring-boot-starter-web<span ><span ><span ></</span>artifactId</span><span >></span></span>
        <span ><span ><span ><</span>exclusions</span><span >></span></span>
            <span ><span ><span ><</span>exclusion</span><span >></span></span>
                <span ><span ><span ><</span>groupId</span><span >></span></span>org.springframework.boot<span ><span ><span ></</span>groupId</span><span >></span></span>
                <span ><span ><span ><</span>artifactId</span><span >></span></span>spring-boot-starter-tomcat<span ><span ><span ></</span>artifactId</span><span >></span></span>
            <span ><span ><span ></</span>exclusion</span><span >></span></span>
        <span ><span ><span ></</span>exclusions</span><span >></span></span>
    <span ><span ><span ></</span>dependency</span><span >></span></span>

    <span ><span ><span ><</span>dependency</span><span >></span></span>
        <span ><span ><span ><</span>groupId</span><span >></span></span>org.springframework.boot<span ><span ><span ></</span>groupId</span><span >></span></span>
        <span ><span ><span ><</span>artifactId</span><span >></span></span>spring-boot-starter-test<span ><span ><span ></</span>artifactId</span><span >></span></span>
    <span ><span ><span ></</span>dependency</span><span >></span></span>
    <span ><span ><span ><</span>dependency</span><span >></span></span>
        <span ><span ><span ><</span>groupId</span><span >></span></span>junit<span ><span ><span ></</span>groupId</span><span >></span></span>
        <span ><span ><span ><</span>artifactId</span><span >></span></span>junit<span ><span ><span ></</span>artifactId</span><span >></span></span>
        <span ><span ><span ><</span>scope</span><span >></span></span>test<span ><span ><span ></</span>scope</span><span >></span></span>
    <span ><span ><span ></</span>dependency</span><span >></span></span>
    <span ><!--consul 引用--></span>
    <span ><span ><span ><</span>dependency</span><span >></span></span>
        <span ><span ><span ><</span>groupId</span><span >></span></span>org.springframework.cloud<span ><span ><span ></</span>groupId</span><span >></span></span>
        <span ><span ><span ><</span>artifactId</span><span >></span></span>spring-cloud-starter-consul-discovery<span ><span ><span ></</span>artifactId</span><span >></span></span>
    <span ><span ><span ></</span>dependency</span><span >></span></span>
<span ><span ><span ></</span>dependencies</span><span >></span></span>

</project>
【microcloud-consul-8501】在 /src/main/resources 下创建配置文件 application.yml 配置文件，增加 Consul 配置
server: port: 8501 spring: cloud: consul: host: 127.0.0.1 port: 8500 discovery: tags: version=1.0,author=code health-check-path: /info # 为健康检查的url,由consul定时调用一次判断服务是否可用 health-check-interval: 5s # 检查间隔时间 instance-id: ${spring.application.name}:prod # 注册的服务ID service-name: ${spring.application.name} # 注册的服务名称 prefer-ip-address: true # 是否使用指定IP地址，默认为 false ip-address: 127.0.0.1 # 指定 IP 地址
application: name: microcloud-consul-8501
【microcloud-consul-8501】配置检查健康服务类
package com.microcloud.controller; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RestController; /** * @Auther: xxx */ @RestController public class ConsulController {

<span >@GetMapping</span><span >(</span>value <span >=</span> <span >"/echo"</span><span >)</span>
<span >public</span> <span >String</span> <span >echo</span><span >(</span><span >String</span> message<span >)</span> <span >{</span>
    <span >return</span> <span >"Echo:"</span> <span >+</span> message<span >;</span>
<span >}</span>

<span >/**
 * consul 检查服务方法
 * @return
 */</span>
<span >@GetMapping</span><span >(</span>value <span >=</span> <span >"/info"</span><span >)</span>
<span >public</span> <span >String</span> <span >info</span><span >(</span><span >)</span> <span >{</span>
    <span >return</span> <span >"info"</span><span >;</span>
<span >}</span>

}
【microcloud-consul-8501】启动类
package com.microcloud; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication;
/**
@Auther: xxx
*/
@SpringBootApplication
public class Application {
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}
}

启动，测试

启动后可得到类似如下内容,即表示注册成功，可通过 Consul UI 地址查看到对应在服务信息

Registering service with consul: NewService{id='microcloud-consul-8501-prod', name='microcloud-consul-8501', tags=[version=1.0, author=code, secure=false], address='127.0.0.1', meta=null, port=8501, enableTagOverride=null, check=Check{script='null', interval='5s', ttl='null', http='http://127.0.0.1:8501/info', method='null', header={}, tcp='null', timeout='null', deregisterCriticalServiceAfter='null', tlsSkipVerify=null, status='null'}, checks=null}

访问: http://localhost:8500/v1/agent/services 将获取如下内容

{
  "microcloud-consul-8501-prod": {
    "ID": "microcloud-consul-8501-prod",
    "Service": "microcloud-consul-8501",
    "Tags": [
      "version=1.0",
      "author=code",
      "secure=false"
    ],
    "Meta": {},
    "Port": 8501,
    "Address": "127.0.0.1",
    "Weights": {
      "Passing": 1,
      "Warning": 1
    },
    "EnableTagOverride": false
  }
}

【microcloud-customer-80】通过 RestTemplate 调用在 Consul 中注册的服务,创建并配置「microcloud-customer-80」模块

配置 pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <parent>
        <artifactId>microcloud</artifactId>
        <groupId>com.microcloud</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>
    <artifactId>microcloud-customer-80</artifactId>

<span ><span ><span ><</span>name</span><span >></span></span>microcloud-customer-80<span ><span ><span ></</span>name</span><span >></span></span>
<span ><!-- FIXME change it to the project's website --></span>
<span ><span ><span ><</span>url</span><span >></span></span>http://www.example.com<span ><span ><span ></</span>url</span><span >></span></span>

<span ><span ><span ><</span>dependencies</span><span >></span></span>
    <span ><span ><span ><</span>dependency</span><span >></span></span>
        <span ><span ><span ><</span>groupId</span><span >></span></span>org.springframework.boot<span ><span ><span ></</span>groupId</span><span >></span></span>
        <span ><span ><span ><</span>artifactId</span><span >></span></span>spring-boot-starter-jetty<span ><span ><span ></</span>artifactId</span><span >></span></span>
    <span ><span ><span ></</span>dependency</span><span >></span></span>
    <span ><span ><span ><</span>dependency</span><span >></span></span>
        <span ><span ><span ><</span>groupId</span><span >></span></span>org.springframework.boot<span ><span ><span ></</span>groupId</span><span >></span></span>
        <span ><span ><span ><</span>artifactId</span><span >></span></span>spring-boot-starter-web<span ><span ><span ></</span>artifactId</span><span >></span></span>
        <span ><span ><span ><</span>exclusions</span><span >></span></span>
            <span ><span ><span ><</span>exclusion</span><span >></span></span>
                <span ><span ><span ><</span>groupId</span><span >></span></span>org.springframework.boot<span ><span ><span ></</span>groupId</span><span >></span></span>
                <span ><span ><span ><</span>artifactId</span><span >></span></span>spring-boot-starter-tomcat<span ><span ><span ></</span>artifactId</span><span >></span></span>
            <span ><span ><span ></</span>exclusion</span><span >></span></span>
        <span ><span ><span ></</span>exclusions</span><span >></span></span>
    <span ><span ><span ></</span>dependency</span><span >></span></span>
    <span ><span ><span ><</span>dependency</span><span >></span></span>
        <span ><span ><span ><</span>groupId</span><span >></span></span>org.springframework.boot<span ><span ><span ></</span>groupId</span><span >></span></span>
        <span ><span ><span ><</span>artifactId</span><span >></span></span>spring-boot-starter-test<span ><span ><span ></</span>artifactId</span><span >></span></span>
    <span ><span ><span ></</span>dependency</span><span >></span></span>
    <span ><!--consul 引用--></span>
    <span ><span ><span ><</span>dependency</span><span >></span></span>
        <span ><span ><span ><</span>groupId</span><span >></span></span>org.springframework.cloud<span ><span ><span ></</span>groupId</span><span >></span></span>
        <span ><span ><span ><</span>artifactId</span><span >></span></span>spring-cloud-starter-consul-discovery<span ><span ><span ></</span>artifactId</span><span >></span></span>
    <span ><span ><span ></</span>dependency</span><span >></span></span>
<span ><span ><span ></</span>dependencies</span><span >></span></span>

</project>

创建 Rest 配置模板 Bean

package com.microcloud.config;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.client.RestTemplate;
/**
 * Rest 模板配置
 * @Auther: xxx
 */
@Configuration
public class RestConfig {
    @Bean
    public RestTemplate getRestTemplate() {
        return new RestTemplate();
    }
}

Rest控制服务

package com.microcloud.controller;

import org.springframework.cloud.client.ServiceInstance;import org.springframework.cloud.client.discovery.DiscoveryClient;import org.springframework.util.CollectionUtils;import org.springframework.web.bind.annotation.GetMapping;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RestController;import org.springframework.web.client.RestTemplate;import javax.annotation.Resource;import java.net.URI;import java.util.List;/**

@Auther: xxx*/@RestController@RequestMapping(value = "/customer")public class CustomerController {

@Resourceprivate RestTemplate restTemplate;@Resourceprivate DiscoveryClient discoveryClient;

@GetMapping(value = "/info")public String getInfo(String echo) {String serviceName = "microcloud-consul-8501";List<ServiceInstance> instances = discoveryClient.getInstances(serviceName);if (!CollectionUtils.isEmpty(instances)) {URI uri = instances.get(0).getUri();String result = restTemplate.getForObject(uri + "/echo?message=" + echo, String.class);return result;}return "";}}

YAMl配置文件

server:
  port: 80
spring:
  application:
    name: customer
  cloud:
    consul:
      host: 127.0.0.1
      port: 8500

服务启动

package com.microcloud;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

/**

@Auther: xxx*/@SpringBootApplicationpublic class Application {public static void main(String[] args) {SpringApplication.run(Application.class, args);}}

在浏览器中输入 http://localhost/customer/info?echo=Hello Consul 观察返回结果

如若无误会得到

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