linux中keepalived實現nginx高可用配置

安裝keepalived

執行如下命令即可
tar -zxvf keepalived-2.0.8.tar.gz -C /usr/src

cd /usr/src/keepalived-2.0.8

sudo apt-get install autoconf

aclocal

autoconf

autoheader

automake --add-missing

sudo apt-get install libssl-dev

./configure --prefix=/usr/local/keepalived

make && make install

cd /usr/local/keepalived/sbin

./keepalived

ps -ef | grep keepalived
 

修改keepalived配置檔案

keepalived的作用，基本上是和多臺nginx伺服器通訊，當主伺服器宕機，將ip分法給備用伺服器

例如，寫類似如下程式碼
    在你的linux網絡卡中新增一個ip地址，這個ip地址可以ping通，也就是多個nginx伺服器，可以共用這一個ip，通過keepalived決定誰可以擁有這個ip
    ip addr add yourtestip dev ens33
    ip addr
    ping yourtestip

配置keepalived配置檔案
sudo vim /usr/local/keepalived/etc/keepalived/keepalived.conf

    ! Configuration File for keepalived
    global_defs {
        # 伺服器宕機發送通知郵件
        notification_email {
            
 
[email protected]
        }
        notification_email_from [email protected]
        smtp_server 192.168.200.1
        smtp_connect_timeout 30
        router_id LVS_DEVEL
        vrrp_skip_check_adv_addr
        vrrp_strict
        vrrp_garp_interval 0
        vrrp_gna_interval 0
    }

    # 虛擬路由器配置
    vrrp_instance VI_1 {
        state MASTER                                # 設定當前nginx伺服器為主節點，備用nginx伺服器對應設定成BACKUP即可
        interface eth0                              # 繫結伺服器網絡卡
        virtual_router_id 51                        # 主備nginx伺服器此id必須一致
        priority 100                                # 設定優先順序，1-254之間，備用伺服器的結點優先順序設定低點
        advert_int 1                                # 資訊傳送間隔，主備都要一致
        authentication {                            # 授權資訊，主備伺服器一致
            auth_type PASS
            auth_pass 1111
        }
        virtual_ipaddress {                         # 虛擬IP，主備伺服器必須一致，網段必須和nginx一致
            192.168.200.16
        }

        notify_master "/usr/local/keepalived/sbin/notify_sh master"  # 主伺服器宕機，備用伺服器要成為主伺服器則呼叫此指令碼
        notify_backup "/usr/local/keepalived/sbin/notify_sh backup"
        notify_fault "/usr/local/keepalived/sbin/notify_sh fault"
    }

    vrrp_script chk_health {
        script "[[`ps -ef | grep nginx | grep -v grep | wc -l`-ge 2]] && exit 0 || exit 1"          # 判斷nginx程序是否大於等於2
        interval 1          # 1秒鐘執行一次
        weight -2           # nginx宕機，本機權重降低2
    }

    track_script {
        chk_health          # 檢查nginx
    }

notify_sh指令碼

    #!/bin/bash
    case $1 in 
        master)
            /usr/local/nginx/sbin/nginx
            exit 0
            ;;
        backup)
            /usr/local/nginx/sbin/nginx -s stop
            /usr/local/nginx/sbin/nginx
            exit 0
            ;;
        fault)
            /usr/local/nginx/sbin/nginx -s stop
            exit 0
        *)
            echo "(notify.sh(master|backup|fault)"
            exit 1
        ;;
    esac