近来公司需要研究consul作为技术储备，本人研究了一下，所谓好记性不如烂笔头子，所以在此记录一下，也希望能帮助到需要的小伙伴，因本人技术能力有限，文章可能有不足或者错误之处，请大神指摘，好及时更改，及时刷新自己的认知。

        由于集群和负载均衡需要多台服务器测试，公司临时也没有多余服务器，所以用了虚拟机。 本文使用了两台虚拟linux作为springboot业务服务，当然你也可以使用docker。

        物理机：Mac OS X 10.13.3

        虚拟机软件：VMware-Fusion-10.1.1

        虚拟机操作系统：CentOS-7

        开发工具：IntelliJ IDEA 2017.2.7

下面我们正式开始

[gerrard@consul ~]#unzip consul_1.0.7_linux_amd64.zip
[gerrard@consul ~]#mv consul /usr/bin/

[gerrard@consul ~]#consul agent -server -bootstrap -ui -bind 192.168.188.182 -client 192.168.188.182 -data-dir /home/gerrard/tmp/consul -node=gerrard_server01

[gerrard@consul ~]#nohup  consul agent -server -bootstrap -ui -bind 192.168.188.182 -client 192.168.188.182 -data-dir /home/gerrard/tmp/consul -node=gerrard_server01  &

[gerrard@consul ~]#consul agent -data-dir /home/gerrard/tmp/consul_agent1  -node=gerrard_agent1 -bind=192.168.188.71 -join=192.168.188.182
[gerrard@consul ~]#consul agent -data-dir /home/gerrard/tmp/consul_agent2  -node=gerrard_agent2 -bind=192.168.185.185 -join=192.168.188.182

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">
	<modelVersion>4.0.0</modelVersion>

	<groupId>com.gerrard</groupId>
	<artifactId>cloud-consul</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<packaging>jar</packaging>

	<name>cloud-consul</name>
	<description>Demo project for Spring Boot</description>

	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>2.0.1.RELEASE</version>
		<relativePath/> <!-- lookup parent from repository -->
	</parent>

	<properties>
		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
		<java.version>1.8</java.version>
		<spring-cloud.version>Finchley.RC1</spring-cloud.version>
	</properties>

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

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
		</dependency>
	</dependencies>

	<dependencyManagement>
		<dependencies>
			<dependency>
				<groupId>org.springframework.cloud</groupId>
				<artifactId>spring-cloud-dependencies</artifactId>
				<version>${spring-cloud.version}</version>
				<type>pom</type>
				<scope>import</scope>
			</dependency>
		</dependencies>
	</dependencyManagement>

	<build>
		<plugins>
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
			</plugin>
		</plugins>
	</build>

	<repositories>
		<repository>
			<id>spring-milestones</id>
			<name>Spring Milestones</name>
			<url>https://repo.spring.io/milestone</url>
			<snapshots>
				<enabled>false</enabled>
			</snapshots>
		</repository>
	</repositories>


</project>

application.properties

spring.cloud.consul.host=localhost
spring.cloud.consul.port=8500
spring.cloud.consul.discovery.health-check-interval=10s
spring.cloud.consul.discovery.instance-id=spring-boot-consul
spring.cloud.consul.discovery.tags=test


spring.application.name=spring-boot-consul
server.port=8080

CloudConsulApplication.class

package com.gerrard.cloudconsul;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;

@SpringBootApplication
@EnableDiscoveryClient
public class CloudConsulApplication {

	public static void main(String[] args) {
		SpringApplication.run(CloudConsulApplication.class, args);
	}
}

HelloWorld.java

package com.gerrard.cloudconsul.ctrl;

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class HelloWorld {

    @RequestMapping("/")
    public String index() {
        return "This is index！ From gerrard_agent 1!";
    }

    @RequestMapping("/hello")
    public String hello() {
        return "Hello World！ From gerrard_agent 1!";
    }
}

package com.gerrard.cloudconsul.ctrl;

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class HelloWorld {

    @RequestMapping("/")
    public String index() {
        return "This is index！ From gerrard_agent 2!";
    }

    @RequestMapping("/hello")
    public String hello() {
        return "Hello World！ From gerrard_agent 2!";
    }
}

[gerrard@nginx /]# cd /usr/src/
[gerrard@nginx src /]# tar -zxvf nginx-1.12.2.tar.gz
[gerrard@nginx src]# yum -y install gcc gcc-c++ make openssl-devel pcre-devel
[gerrard@nginx src]# cd nginx-1.12.2/
[gerrard@nginx nginx-1.12.2]# ./configure --prefix=/usr/local/nginx   --with-http_stub_status_module --with-http_realip_module --with-pcre  --with-http_ssl_module
[gerrard@nginx nginx-1.12.2]# make -j 2
[gerrard@nginx nginx-1.12.2]# make install

启动nginx

[gerrard@nginx nginx-1.12.2]# /usr/local/nginx/sbin/nginx

[gerrard@nginx ]# unzip consul-template_0.19.3_linux_amd64.zip[gerrard@nginx ]# mv consul-template /usr/bin/

upstream http_backend {
    {{range service "spring-boot-consul"}}
    server {{ .Address }}:{{ .Port }};
    {{ end }}
}

server {
    listen 8000;
    server_name localhost;
    location / {
    proxy_pass http://http_backend;
    }
}

简单描述下模板：upstream 定义一个简单的模板，server监听8000端口（你自己随便改，只要不被占用就行），反向代理到upstream。

7.2 修改nginx.conf

打开nginx.conf

[gerrard@nginx consul]# vim /usr/local/nginx/conf/nginx.conf

在server同级处，添加一句 include /usr/local/nginx/consul/*.conf; 如下图：

切记不要写错位置，否则你永远也访问不到你代理的地址。

配置完毕，需要重新加载nginx

[gerrard@nginx consul]# /usr/local/nginx/sbin/nginx  -s reload

[gerrard@consul]# consul-template --consul-addr 192.168.188.182:8500 --template "./nginx.ctmpl:vhost.conf:/usr/local/nginx/sbin/nginx -s reload" --log-level=info

查看配置：

[gerrard@consul]# cat /usr/local/nginx/consul/vhost.conf