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Centos7 Nginx配合 keepalived+vip高可用安装部署配置
因为SRS高可用，在前一个版本还只是单机版的nginx,因此宕机后会无法使用了，因此配合keepalived+vip实现故障转移
因此规划
192.168.100.47为主服务器，192.168.100.48是从服务器，192.168.100.49为漂移的VIP
主服务器配置（192.168.100.47）：
第一步：安装keepalived
yum install -y keepalived
第二步：修改配置文件
cp /etc/keepalived/keepalived.conf /etc/keepalived/keepalived.conf.bak
vi /etc/keepalived/keepalived.conf
[root@host147 ~]# cat /etc/keepalived/keepalived.conf
global_defs {
# 路由id：当前安装keepalived的节点主机标识符，保证全局唯一
router_id keep_host147
#vrrp_skip_check_adv_addr
#vrrp_strict
#vrrp_garp_interval 0
#vrrp_gna_interval 0
}
vrrp_script check_web {
script "/etc/keepalived/check_web.sh" # 脚本存放的位置
interval 2 # 每隔两秒运行上一行脚本
weight -20 # 如果脚本运行成功，则升级权重-20，自动切换到备
}
vrrp_instance VI_1 {
# 主机=MASTER;备用机=BACKUP
state MASTER
# 该实例绑定的网卡名称
interface ens33
# 保证主备节点一致
virtual_router_id 51
# 权重，master值 > backup值
priority 100
# 主备组播报发送间隔时间1秒
advert_int 1
# 认证权限密码，防止非法节点进入
authentication {
auth_type PASS
auth_pass 1111
}
# 虚拟出来的ip，可以有多个（vip）
virtual_ipaddress {
192.168.100.149
}
# 调用监控脚本
track_script {
check_web
}
}
第三步：编写nginx监控脚本
如果nginx服务停止，keepalived服务也停止，并切换到备主机
脚本如下：
#[root@host147 ~]# cat /etc/keepalived/check_web.sh
#!/bin/bash
num=`ps -C nginx --no-header |wc -l`
if [ $num -eq 0 ]
then
systemctl stop keepalived
fi
第四步：启动、开机自启keepalived服务
[root@host147 ~]# systemctl start keepalived
[root@host147 ~]# systemctl enable keepalived
第五步：查看keepalived服务状态；查看虚拟IP生效情况；
[root@host147 ~]# ip a
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:29:9a:aa:ef brd ff:ff:ff:ff:ff:ff
inet 192.168.100.147/24 brd 192.168.100.255 scope global noprefixroute ens33
valid_lft forever preferred_lft forever
inet 192.168.100.149/32 scope global ens33
valid_lft forever preferred_lft forever
inet6 fe80::eec8:aaa1:fa6d:cf50/64 scope link noprefixroute
valid_lft forever preferred_lft forever
[root@host147 ~]#
[root@host147 ~]#
[root@host147 ~]# ps -ef|grep keepalived
root 7404 1 0 09:58 ? 00:00:00 /usr/sbin/keepalived -D
root 7405 7404 0 09:58 ? 00:00:00 /usr/sbin/keepalived -D
root 7406 7404 0 09:58 ? 00:00:00 /usr/sbin/keepalived -D
root 7556 7199 0 09:58 pts/0 00:00:00 grep --color=auto keepalived
[root@host147 ~]#
从服务器配置（192.168.100.48）：
第一步：安装keepalived
参考主服务器
第二步：修改配置文件
cp /etc/keepalived/keepalived.conf /etc/keepalived/keepalived.conf.bak
vi /etc/keepalived/keepalived.conf
[root@host148 ~]# cat /etc/keepalived/keepalived.conf
global_defs {
# 路由id：当前安装keepalived的节点主机标识符，保证全局唯一
router_id keep_host148
#vrrp_skip_check_adv_addr
#vrrp_strict
#vrrp_garp_interval 0
#vrrp_gna_interval 0
}
vrrp_script check_web {
script "/etc/keepalived/check_web.sh" # 脚本存放的位置
interval 2 # 每隔两秒运行上一行脚本
weight -20 # 如果脚本运行成功，则升级权重-20，自动切换到备
}
vrrp_instance VI_1 {
# 主机=MASTER;备用机=BACKUP
state BACKUP
# 该实例绑定的网卡名称
interface ens33
# 保证主备节点一致
virtual_router_id 51
# 权重，master值 > backup值
priority 88
# 主备组播报发送间隔时间1秒
advert_int 1
# 认证权限密码，防止非法节点进入
authentication {
auth_type PASS
auth_pass 1111
}
# 虚拟出来的ip，可以有多个（vip）
virtual_ipaddress {
192.168.100.149
}
# 调用监控脚本
track_script {
check_web
}
}
**第三步：编写nginx监控脚本 **
参考主服务器
第四步：启动、开机自启keepalived服务
参考主服务器
第五步：查看keepalived服务状态
参考主服务器
测试高可用
如果主服务器nginx服务停止，则自动切换到备主机
查看主从服务器 keepalived + nginx 服务都处于开启的状态
[root@host147 ~]# ps -ef|grep "nginx\|keepalived"
root 6966 1 0 09:55 ? 00:00:00 nginx: master process /usr/sbin/nginx -c /etc/nginx/nginx.conf
nginx 6968 6966 0 09:55 ? 00:00:00 nginx: worker process
root 7404 1 0 09:58 ? 00:00:00 /usr/sbin/keepalived -D
root 7405 7404 0 09:58 ? 00:00:00 /usr/sbin/keepalived -D
root 7406 7404 0 09:58 ? 00:00:00 /usr/sbin/keepalived -D
root 8177 7199 0 10:02 pts/0 00:00:00 grep --color=auto nginx\|keepalived
[root@host148 ~]# ps -ef|grep "nginx\|keepalived"
root 7024 1 0 09:55 ? 00:00:00 nginx: master process /usr/sbin/nginx -c /etc/nginx/nginx.conf
nginx 7025 7024 0 09:55 ? 00:00:00 nginx: worker process
root 7422 1 0 10:03 ? 00:00:00 /usr/sbin/keepalived -D
root 7423 7422 0 10:03 ? 00:00:00 /usr/sbin/keepalived -D
root 7424 7422 0 10:03 ? 00:00:00 /usr/sbin/keepalived -D
root 7493 7202 0 10:03 pts/0 00:00:00 grep --color=auto nginx\|keepalived
查看虚拟IP在主服务器，因此访问虚拟IP则先到主服务器，然后停止主服务器 nginx 服务，并查看nginx + keepalived服务状态
[root@host147 ~]# systemctl stop nginx
[root@host147 ~]#
[root@host147 ~]#
[root@host147 ~]# ps -ef|grep "nginx\|keepalived"
root 8532 7199 0 10:05 pts/0 00:00:00 grep --color=auto nginx\|keepalived
查看是否已经自动切换到从服务器
[root@host148 ~]# ip a
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:d7:9f:0a brd ff:ff:ff:ff:ff:ff
inet 192.168.100.148/24 brd 192.168.100.255 scope global noprefixroute ens33
valid_lft forever preferred_lft forever
inet 192.168.100.149/32 scope global ens33
valid_lft forever preferred_lft forever
inet6 fe80::eec8:aaa1:fa6d:cf50/64 scope link tentative noprefixroute dadfailed
valid_lft forever preferred_lft forever
inet6 fe80::dabf:7345:e6bd:52aa/64 scope link noprefixroute
valid_lft forever preferred_lft forever
继续浏览器访问虚拟IP也可以访问成功！
牛啊,高深莫测!!!