1. nginx部署
单机部署可参考：https://blog.csdn.net/ym5209999/article/details/119897237
2. keepalived安装
[root@nginx1 ~]# yum -y install keepalived
3. keepalived配置
3.1 安装完成后，默认配置文件位于：/etc/keepalived，默认配置如下：
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 eth0
virtual_router_id 51
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.200.16
192.168.200.17
192.168.200.18
}
}
virtual_server 192.168.200.100 443 {
delay_loop 6
lb_algo rr
lb_kind NAT
persistence_timeout 50
protocol TCP
real_server 192.168.201.100 443 {
weight 1
SSL_GET {
url {
path /
digest ff20ad2481f97b1754ef3e12ecd3a9cc
}
url {
path /mrtg/
digest 9b3a0c85a887a256d6939da88aabd8cd
}
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
}
virtual_server 10.10.10.2 1358 {
delay_loop 6
lb_algo rr
lb_kind NAT
persistence_timeout 50
protocol TCP
sorry_server 192.168.200.200 1358
real_server 192.168.200.2 1358 {
weight 1
HTTP_GET {
url {
path /testurl/test.jsp
digest 640205b7b0fc66c1ea91c463fac6334d
}
url {
path /testurl2/test.jsp
digest 640205b7b0fc66c1ea91c463fac6334d
}
url {
path /testurl3/test.jsp
digest 640205b7b0fc66c1ea91c463fac6334d
}
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
real_server 192.168.200.3 1358 {
weight 1
HTTP_GET {
url {
path /testurl/test.jsp
digest 640205b7b0fc66c1ea91c463fac6334c
}
url {
path /testurl2/test.jsp
digest 640205b7b0fc66c1ea91c463fac6334c
}
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
}
virtual_server 10.10.10.3 1358 {
delay_loop 3
lb_algo rr
lb_kind NAT
persistence_timeout 50
protocol TCP
real_server 192.168.200.4 1358 {
weight 1
HTTP_GET {
url {
path /testurl/test.jsp
digest 640205b7b0fc66c1ea91c463fac6334d
}
url {
path /testurl2/test.jsp
digest 640205b7b0fc66c1ea91c463fac6334d
}
url {
path /testurl3/test.jsp
digest 640205b7b0fc66c1ea91c463fac6334d
}
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
real_server 192.168.200.5 1358 {
weight 1
HTTP_GET {
url {
path /testurl/test.jsp
digest 640205b7b0fc66c1ea91c463fac6334d
}
url {
path /testurl2/test.jsp
digest 640205b7b0fc66c1ea91c463fac6334d
}
url {
path /testurl3/test.jsp
digest 640205b7b0fc66c1ea91c463fac6334d
}
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
}
3.2 按实际情况修改keepalived.conf
主
! Configuration File for keepalived
global_defs {
# 路由ID，当前主机标识，必须唯一
router_id LVS_DEVEL_144
script_user root
enable_script_security
}
vrrp_instance VI_1 {
# 状态，可配置内容为：MASTER/BACKUP
state MASTER
# 网卡名称
interface ens192
# 主备节点需保持一致
virtual_router_id 51
# 优先级，当主节点宕机后，优先级最高的成为主节点
priority 100
# 主备同步时间间隔
advert_int 1
# 认证授权密码
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.2.198 # 虚拟IP
}
}
备
! Configuration File for keepalived
global_defs {
# 路由ID，当前主机标识，必须唯一
router_id LVS_DEVEL_62
script_user root
enable_script_security
}
vrrp_instance VI_1 {
# 状态，可配置内容为：MASTER/BACKUP
state BACKUP
# 网卡名称
interface ens192
# 主备节点需保持一致
virtual_router_id 51
# 优先级，当主节点宕机后，优先级最高的成为主节点
priority 80
# 主备同步时间间隔
advert_int 1
# 认证授权密码
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.2.198 # 虚拟IP
}
}
4. 启动验证
# 启动nginx
[root@nginx1 ~]# /apps/nginx/sbin/nginx –c /apps/nginx/conf/nginx.conf
# 启动keepalived
[root@nginx1 ~]# systemctl start keepalived
1）启动完成后，查看主节点IP地址，在ens192下生成虚拟IP后，即可访问：192.168.2.198查看效果（在配置文件中，主节点priority 值大于备节点，故会生成在主节点）；
2）将主节点keepalived服务结束后，再次访问192.168.2.198，会自动切换到备节点
5. 优化
当nginx服务器挂掉之后，由于keepalived服务保持正常，故VIP依旧保留在进程异常的服务器上，导致前端无法自动切换，故需要对配置进行优化。
优化点：定期检测nginx进程活性，若nginx服务不存在，则重启nginx服务，若无法启动，则将keepalived进程结束，使之正常切换到正常的keepalived。
nginx活性检测脚本：
nginx_check.sh
#!/bin/bash
A=`ps -C nginx --no-header |wc -l` #查看是否有进程，把值赋给变量A
if [ $A -eq 0 ];then #如果没有进程值则为0
/apps/nginx/sbin/nginx –c /apps/nginx/conf/nginx.conf #nginx的启动路径
sleep 5 #尝试启动nginx等待5秒
B=`ps -C nginx --no-header |wc -l`
if [ $B -eq 0 ];then #在查看一下是否有进程，没有则结束，杀掉keepalived
systemctl stop keepalived
fi
fi
将脚本上传至主、备服务器：/etc/keepalived/目录下，并授权（不能授权为777！！！）
chmod -R 755 nginx_check.sh
建议在启动验证的时候，打印系统日志，同步查看：tail -f /var/log/messages
主
! Configuration File for keepalived
global_defs {
# 路由ID，当前主机标识，必须唯一
router_id LVS_DEVEL_144
script_user root
enable_script_security
}
# ----------------------- 新增点 ------------------------
vrrp_script nginxcheck {
script "/etc/keepalived/nginx_check.sh"
interval 10
}
# ----------------------- 新增点 ------------------------
vrrp_instance VI_1 {
# 状态，可配置内容为：MASTER/BACKUP
state MASTER
# 网卡名称
interface ens192
# 主备节点需保持一致
virtual_router_id 51
# 优先级，当主节点宕机后，优先级最高的成为主节点
priority 100
# 主备同步时间间隔
advert_int 1
# 认证授权密码
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.2.198
}
# ----------------------- 新增点 ------------------------
track_script {
nginxcheck
}
# ----------------------- 新增点 ------------------------
}
备
! Configuration File for keepalived
global_defs {
# 路由ID，当前主机标识，必须唯一
router_id LVS_DEVEL_62
script_user root
enable_script_security
}
# ----------------------- 新增点 ------------------------
vrrp_script nginxcheck {
script "/etc/keepalived/nginx_check.sh"
interval 10
}
# ----------------------- 新增点 ------------------------
vrrp_instance VI_1 {
# 状态，可配置内容为：MASTER/BACKUP
state BACKUP
# 网卡名称
interface ens192
# 主备节点需保持一致
virtual_router_id 51
# 优先级，当主节点宕机后，优先级最高的成为主节点
priority 80
# 主备同步时间间隔
advert_int 1
# 认证授权密码
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.2.198
}
# ----------------------- 新增点 ------------------------
track_script {
nginxcheck
}
# ----------------------- 新增点 ------------------------
}
6. 验证
1）按上述配置完成后，重启keepalived，验证是否能把nginx进程自动拉起；
2）手动结束nginx进程，并故意将nginx_check.sh中nginx启动命令调整为错误命令，尝试是否会将对应节点keepalived进程自动结束。
