需求

通過某一確定ip和埠訪問tcp服務的主從機，某一服務器宕機，需要自動切換為另外一正常的節點，另外需要對主從機負載均衡，由keepalived虛擬出一個ip，通過這個虛擬ip連接到多臺nginx，每臺nginx反向代理到tcp服務各節點來實作負載均衡，

安裝nignx

下載安裝包
解壓 tar zxvf nginx-1.21.1.tar.gz
##代理tcp時，此處必須加上–with-stream引數
./configure --with-stream
make && make install
經過上述操作，nignx安裝完畢，安裝目標在 /usr/local/nginx中

安裝libnl

下載libnl-3.5.0.tar.gz安裝包
解壓 tar zxvf libnl-3.5.0.tar.gz
./configure
make && make install

安裝keepalived

下載keepalived-2.2.1.tar.gz
解壓 keepalived-2.2.1.tar.gz
添加自啟動功能 cp keepalived-2.2.1/keepalived/etc/init.d/keepalived /etc/init.d
ln -s /lib/x86_64-linux-gnu/libnl-genl-3.so.200 /lib/x86_64-linux-gnu/libnl-genl-3.so
./configure --prefix=/usr/local/keepalived
make && make install
mkdir -p /etc/keepalived
cp /usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived
keepalived安裝完畢，安裝目標在/usr/local/keepalived中，

配置部署nginx

分別編輯兩臺服務器上的nginx組態檔，配置代理埠號和負載均衡服務器串列
vi /usr/local/nginx/conf/nginx.conf

#user  nobody;
worker_processes  1;   #啟動行程,通常設定成和cpu的核數相等

error_log  logs/error.log;
# error_log  logs/error.log  notice;
# error_log  logs/error.log  info;

pid        logs/nginx.pid;


events {
    worker_connections  1024;
}

stream {
    server {
        listen 10000;
        proxy_pass app;
        proxy_connect_timeout 5;
    }
 
    upstream app {
         #設定負載均衡的服務器串列  
        server 192.168.43.131:9999 weight=1;
        server 192.168.43.132:9999 weight=1;
    }
}

啟動nginx
cd /usr/local/nginx/sbin
chmod +x nginx
./nginx
ps -ef | grep nginx

配置部署keepalived

分別編輯兩臺服務器上的keepalived組態檔，注意check_nginx.sh腳本的存放位置，check_nginx.sh用來判斷nginx行程是否運行，
vi /etc/keepalived/keepalived.conf
master配置

global_defs {
    router_id LVS_DEVEL
}

vrrp_script check_gateway {
    script "/home/wangchao/check_nginx.sh"
   interval 2
    weight -5
    fall 2
    rise 1
}

vrrp_instance VI_1 {
    state MASTER
    interface eth0
    virtual_router_id 51
    priority 100
    advert_int 1
    mcast_src_ip 192.168.43.131
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    track_script {
        check_gateway
    }
    virtual_ipaddress {
        192.168.43.200
    }
}

backup配置

global_defs {
    router_id LVS_DEVEL
}

vrrp_script check_gateway {
    script "/home/wangchao/check_nginx.sh"
   interval 2
    weight -5
    fall 2
    rise 1
}

vrrp_instance VI_1 {
    state BACKUP
    interface eth0
    virtual_router_id 51
    priority 99
    advert_int 1
    mcast_src_ip 192.168.43.132
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    track_script {
        check_gateway
    }
    virtual_ipaddress {
        192.168.43.200
    }
}

檢驗nginx是否運行的腳本check_nginx.sh

#!/bin/bash
appName='nginx'
appPid=$(ps -ef | grep "${appName}" |grep -v grep| awk  '{print $2}'| awk 'NR==1')
if [ ! $appPid ];then
        service keepalived stop
fi

兩臺服務器上都啟動Tcp服務
最后啟動keepalived
systemctl start keepalived