CentOS 7 使用 keepalived 搭建 nginx 高可用服務器簡略教程

安裝nginx請看教程。

本機測試環境爲CentOS7。主服務器192.168.126.130，從服務器192.168.126.129，VIP IP 192.168.126.188。

安裝keepalived。

[root@promote ~]# yum install -y keepalived
[root@promote ~]# cd /etc/keepalived/
#主服務器修改網頁信息，非必須操做
[root@promote ~]# echo "master nginx web server." > /usr/local/nginx/html/index.html 
#從服務器修改網頁信息，非必須操做
[root@promote ~]# echo "slave nginx web server." > /usr/local/nginx/html/index.html 
[root@promote ~]# vim keepalived.conf

主服務器配置信息以下：

[root@promote ~]# cat /etc/keepalived/keepalived.conf
! Configuration File for keepalived

global_defs {
   notification_email {
     acassen@firewall.loc
     failover@firewall.loc
     sysadmin@firewall.loc
   }
   notification_email_from Alexandre.Cassen@firewall.loc
   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
}

vrrp_instance VI_1 {
    state MASTER
    interface ens33
    virtual_router_id 51
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.126.188
    }
}
[root@promote ~]
# 
vrrp_instance VI_1 {
    state MASTER #主從服務器狀態，主服務器down後切換到backup
    interface ens33 #網卡名稱
    virtual_router_id 51
    priority 100 #服務器優先級
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.126.188 #VIP地址
    }
}

從服務器配置。

[root@promote sbin]# cat /etc/keepalived/keepalived.conf
! Configuration File for keepalived

global_defs {
   notification_email {
     acassen@firewall.loc
     failover@firewall.loc
     sysadmin@firewall.loc
   }
   notification_email_from Alexandre.Cassen@firewall.loc
   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
}

vrrp_instance VI_1 {
    state BACKUP
    interface ens33
    virtual_router_id 51
    priority 90
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.126.188
    }
}
[root@promote sbin]#

細心讀者會發現郵件地址爲192.168.200.1，郵件模塊本文未使用，能夠嘗試刪除或修改。

主從服務器啓動keepalived服務。

[root@promote sbin]# service keepalived start

瀏覽器訪問192.168.126.130。Linux查看服務器信息。

[root@promote ~]# curl -i 192.168.126.130
HTTP/1.1 200 OK
Server: nginx/1.14.2
Date: Mon, 08 Apr 2019 04:23:24 GMT
Content-Type: text/html
Content-Length: 25
Last-Modified: Mon, 08 Apr 2019 04:19:05 GMT
Connection: keep-alive
ETag: "5caacbb9-19"
Accept-Ranges: bytes

master nginx web server.
[root@promote ~]# 
#從服務器信息顯示基本一致。

關掉主服務器從新查看瀏覽器信息，nginx 服務器正常訪問。查看服務器IP信息。

#master
[root@promote ~]# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 00:0c:29:f0:04:39 brd ff:ff:ff:ff:ff:ff
    inet 192.168.126.130/24 brd 192.168.126.255 scope global noprefixroute dynamic ens33
       valid_lft 1796sec preferred_lft 1796sec
    inet 192.168.126.188/32 scope global ens33
       valid_lft forever preferred_lft forever
    inet6 fe80::ccc2:d1b:1fc4:8ce2/64 scope link tentative noprefixroute dadfailed 
       valid_lft forever preferred_lft forever
    inet6 fe80::c354:a1e1:869f:7ae1/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever
[root@promote ~]# 
#slave
[root@promote ~]# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 00:0c:29:c3:f7:cb brd ff:ff:ff:ff:ff:ff
    inet 192.168.126.129/24 brd 192.168.126.255 scope global noprefixroute dynamic ens33
       valid_lft 1673sec preferred_lft 1673sec
    inet6 fe80::ccc2:d1b:1fc4:8ce2/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever
[root@promote ~]#

嘗試啓用主服務器關閉從服務器，查看服務器IP信息。

#模擬主服務器down
[root@promote ~]# service keepalived stop
Redirecting to /bin/systemctl stop keepalived.service
[root@promote ~]# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 00:0c:29:f0:04:39 brd ff:ff:ff:ff:ff:ff
    inet 192.168.126.130/24 brd 192.168.126.255 scope global noprefixroute dynamic ens33
       valid_lft 1717sec preferred_lft 1717sec
    inet6 fe80::ccc2:d1b:1fc4:8ce2/64 scope link tentative noprefixroute dadfailed 
       valid_lft forever preferred_lft forever
    inet6 fe80::c354:a1e1:869f:7ae1/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever
[root@promote ~]# 
#自動切換到master
[root@promote ~]# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 00:0c:29:c3:f7:cb brd ff:ff:ff:ff:ff:ff
    inet 192.168.126.129/24 brd 192.168.126.255 scope global noprefixroute dynamic ens33
       valid_lft 1564sec preferred_lft 1564sec
    inet 192.168.126.188/32 scope global ens33
       valid_lft forever preferred_lft forever
    inet6 fe80::ccc2:d1b:1fc4:8ce2/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever
[root@promote ~]#

操做實驗完美實現nginx web服務器自動切換。