keeplived高可用集群

version: "3"
services:
  nginx_master:
    build:
      context: ./
      dockerfile: ./Dockerfile
    volumes:
      - ./index-master.html:/usr/share/nginx/html/index.html
      - ./favicon.ico:/usr/share/nginx/html/favicon.ico
      - ./keepalived-master.conf:/etc/keepalived/keepalived.conf
    networks:
      static-network:
        ipv4_address: 172.20.128.2
    cap_add: 
      - NET_ADMIN
  nginx_slave:
    build:
      context: ./
      dockerfile: ./Dockerfile
    volumes:
      - ./index-slave.html:/usr/share/nginx/html/index.html
      - ./favicon.ico:/usr/share/nginx/html/favicon.ico
      - ./keepalived-slave.conf:/etc/keepalived/keepalived.conf
    networks:
      static-network:
        ipv4_address: 172.20.128.3
    cap_add: 
        - NET_ADMIN
  proxy:
    image: haproxy:1.7-alpine
    ports:
      - 8000:6301
    volumes:
      - ./haproxy.cfg:/usr/local/etc/haproxy/haproxy.cfg
    networks:
      - static-network

networks:
  static-network:
    ipam:
      config:
        - subnet: 172.20.0.0/16

# 使用的基础镜像源(alpine是精简的Linux内核)
FROM nginx:1.13.5-alpine
# 更新最新本地镜像源  && 升级软件
RUN apk update && apk upgrade
# 安装keepalived等相关软件
RUN apk add --no-cache bash curl ipvsadm iproute2 openrc keepalived &&     rm -f /var/cache/apk/* /tmp/*
# 将nginx和keepalive启动脚本从宿主机拷贝到docker容器中
COPY entrypoint.sh /entrypoint.sh
# 给启动脚本添加权限
RUN chmod +x /entrypoint.sh
# 启动服务
CMD ["/entrypoint.sh"]

# vrrp_script区域主要用来做健康检查的，当时检查失败时会将vrrp_instance的priority减少相应的值
vrrp_script chk_nginx {
    script "pidof nginx"
    interval 2
}

# 设置外网的VIP(虚拟ip)
vrrp_instance VI_1 {
    # 可以是MASTER或BACKUP，不过当其他节点keepalived启动时会将priority比较大的节点选举为MASTER
    state MASTER
    # 对外提供服务的网络接口，用来发VRRP包
    interface eth0
    # 取值在0-255之间，用来区分多个instance的VRRP组播， 同一网段中该值不能重复，并且同一个vrrp实例使用唯一的标识
    virtual_router_id 33
    # 用来选举master的，要成为master，那么这个选项的值最好高于其他机器50个点，该项取值范围是1-255（在此范围之外会被识别成默认值100）
    priority 200
    # 发VRRP包的时间间隔，即多久进行一次master选举，可以认为是健康查检时间间隔，单位为秒
    advert_int 1
    # 表示发送VRRP单播报文使用的源IP地址，当前keepalive真实ip
    unicast_src_ip 172.20.128.2
    # 表示对端接收VRRP单播报文的IP地址（防止上游交换机禁用广播）
    unicast_peer {
        172.20.128.3
    }
    
    authentication {
        # 定义认证类型
        auth_type PASS
        # 认证密码  这些相当于暗号
        auth_pass letmein
    }
    # keepalive对外的虚拟地址，访问虚拟地址会访问keepalive的master地址
    virtual_ipaddress {
        172.20.128.4/24 dev eth0
    }
    # track_script用于追踪脚本，用以实现某个检测功能
    track_script {
        chk_nginx
    }
}

# 配置keepalive
virtual_server 172.20.128.2 80 {
    delay_loop 15
    lb_algo rr
    lb_kind DR
    nat_mask 255.255.255.0
    persistence_timeout 50
    protocol TCP

    # keepalive代理的真实服务ip
    real_server 172.16.16.177 80 {
         weight 1
        TCP_CHECK {
            connect_port 80
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 4
        }
    }
    # keepalive代理的真实服务ip
    real_server 172.16.16.178 80 {
        weight 1
        TCP_CHECK {
            connect_port 80
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 4

        }
    }
}

vrrp_script chk_nginx {
    script "pidof nginx"
    interval 2
}

vrrp_instance VI_1 {
    state BACKUP
    interface eth0
    virtual_router_id 33
    priority 100
    advert_int 1
    unicast_src_ip 172.20.128.3
    unicast_peer {
        172.20.128.2
    }
    
    authentication {
        auth_type PASS
        auth_pass letmein
    }
    
    virtual_ipaddress {
        172.20.128.4/24 dev eth0
    }
    
    track_script {
        chk_nginx
    }
}

# global常用配置项
global
    # haproxy默认没有记录日志的文件，需要依赖rsyslog收集，具体方法，首先在配置文件的global段添加一条配置项
    log 127.0.0.1 local0
    # 最大并发连接数；默认为2000
    maxconn 4096
    daemon
    # 要启动的haproxy的进程数量；默认为1个，推荐为1个
    nbproc 4

defaults
    log 127.0.0.1 local3
    mode http
    option dontlognull
    option redispatch
    retries 2
    maxconn 2000
    balance roundrobin
    timeout connect 5000ms
    timeout client 5000ms
    timeout server 5000ms

# frontend部署前端服务，负责给用户请求一个接口
frontend main
    # 监听本docker容器中所有访问6301端口的请求
    # 监听端口，即haproxy提供web服务的端口，和lvs的vip端口类似
    bind *:6301
    # 定义一个服务器组 http_back
    default_backend webserver

# backend可以定义后端一组服务器
backend webserver
    server ngxin_master 172.20.128.4:80 check inter 2000 rise 2 fall 5
# 具体流程就是当frontend接受到用户请求，根据我们的配置交给指定的backend处理请求，backend再将请求分发到真正的后端服务器

#!/bin/sh

/usr/sbin/keepalived -n -l -D -f /etc/keepalived/keepalived.conf --dont-fork --log-console &

nginx -g "daemon off;"

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>主机</title>
<style>

#box{ 
    margin: 0px auto;
    font-family: ‘Times New Roman‘, Times, serif; 
    font-size: 30px;
    font-style: initial;
    color: aliceblue;
    }

body{
    background-color: black
}

</style>
</head>
<body>

    <div id="box">

        主机

    </div>
    
</body>
</html>

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>从机</title>
<style>

#box{ 
    margin: 0px auto;
    font-family: ‘Times New Roman‘, Times, serif; 
    font-size: 30px;
    font-style: initial;
    color: aliceblue;
    }

body{
    background-color: black
}

</style>
</head>
<body>

    <div id="box">

        从机

    </div>
    
</body>
</html>