useradd -r -s /sbin/nologin keepalived_script
chown keepalived_script:keepalived_script /etc/keepalived/check_nginx.sh
chmod 655 /etc/keepalived/check_nginx.sh

/etc/nginx/nginx.conf

user nginx;
worker_processes auto;
error_log /var/log/nginx/error.log;
pid /run/nginx.pid;

# Load dynamic modules. See /usr/share/doc/nginx/README.dynamic.
include /usr/share/nginx/modules/*.conf;

events {
    worker_connections 1024;
}

http {
    upstream demos {
        server 192.168.100.103:80 weight=1;  # 后端web服务器
        server 192.168.100.104:80 weight=1;  # 后端web服务器
    }
    server {
        listen 80;
        location /{
                proxy_pass http://demos/;
        }
    }
}
~           

yum -y install nginx
systemctl start nginx 

echo "<h1>`hostname -I`</h1>" > /usr/share/nginx/html/index.html

! Configuration File for keepalived

global_defs {
   router_id alfie_keepalive_1  # 备用节点修改名称
   vrrp_skip_check_adv_addr
   vrrp_garp_interval 0
   vrrp_gna_interval 0
   vrrp_mcast_group4 224.0.0.18
}

vrrp_script check_nginx {
    script "/etc/keepalived/check_nginx.sh"  # 使用 kill 发送 0 信号 确认程序是否工作正常
    interval 1
    weight -30  # 失败后降低 30 权重
    fall 3
    rise 5
    timeout 2
}

vrrp_instance alfie_ka1 {
    state MASTER  # 备用节点为 BACKUP
    interface ens33
    virtual_router_id 61
    priority 100  # 备用节点默认权重 80
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass alopex
    }
    virtual_ipaddress {
        192.168.100.111/24
    }
    unicast_src_ip 192.168.100.101  # 备用节点修改本地IP
    unicast_peer{
        192.168.100.102  # 备用节点此处填写主节点IP
    }
    track_script {
        check_nginx
    }
}
include /etc/keepalived/conf.d/*.conf

chmod a+x /etc/keepalived/check_nginx.sh
# 文件 /usr/bin/killall -0 nginx

#!/bin/bash
/usr/bin/killall -0 nginx

# 绑定非自身IP地址
vim /etc/sysctl.conf
net.ipv4.ip_nonlocal_bind = 1

sysctl -p

# 在防火墙上放行通对VIP的访问
firewall-cmd --permanent --add-rich-rule='rule family="ipv4" destination address="192.168.100.111" accept' 
firewall-cmd --reload

global
  daemon
  stats socket /var/lib/haproxy/haproxy.sock mode 600 level admin
  nbthread  5

  user haproxy
  group haproxy
  maxconn 100000

defaults
  option http-keep-alive
  maxconn 100000
  mode http
  timeout connect 300000ms
  timeout client 300000ms
  timeout server 300000ms

frontend demo-web-port
  bind 192.168.100.111:80
  mode http
  use_backend demo-web

backend demo-web
  mode http
  default-server inter 1000 weight 6
  server web2 192.168.100.103:80 weight 2 check addr 192.168.100.103 port 80
  server web3 192.168.100.104:80 weight 2 check addr 192.168.100.104 port 80

yum -y install nginx
systemctl start nginx 

echo "<h1>`hostname -I`</h1>" > /usr/share/nginx/html/index.html

! Configuration File for keepalived

global_defs {
   router_id alfie_keepalive_1  # 备用节点修改名称
   vrrp_skip_check_adv_addr
   vrrp_garp_interval 0
   vrrp_gna_interval 0
   vrrp_mcast_group4 224.0.0.18
}

vrrp_script check_haproxy {
    script "/etc/keepalived/check_haproxy.sh"
    interval 1
    weight -30
    fall 3
    rise 5
    timeout 2
}

vrrp_instance alfie_ka1 {
    state MASTER # 备用节点修改为 BACKUP
    interface ens33
    virtual_router_id 61
    priority 100  # 备用节点修改 80
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass alopex
    }
    virtual_ipaddress {
        192.168.100.111/24
    }
    unicast_src_ip 192.168.100.101 # 备用节点修改为本地IP
    unicast_peer{
        192.168.100.102   # 备用节点填主用节点IP
    }
    track_script {
        check_haproxy
    }
}

include /etc/keepalived/conf.d/*.conf

/etc/keepalived/check_haproxy.sh
chmod 655 /etc/keepalived/check_haproxy.sh
#!/bin/bash

if /usr/bin/killall -0 haproxy
then
    exit 0
else
    systemctl restart haproxy
fi

# 修改配置文件
# 以下与cluster相关，按需开启
# -e '/# cluster-enabled yes/a cluster-enabled yes' \
# -e '/# cluster-config-file nodes-6379.conf/a cluster-config-file nodes-6379.conf' \
# -e '/cluster-require-full-coverage yes/a cluster-require-full-coverage no' \

sed -i.bak \
-e 's/appendonly no/appendonly yes/' \
-e '/masterauth/a masterauth alopex' \
-e 's/bind 127.0.0.1/bind 0.0.0.0/'  \
-e "/# requirepass/a requirepass alopex" \
-e "/^dir .*/c dir /apps/redis/data/"  \
-e "/logfile .*/c logfile /apps/redis/log/redis-6379.log" \
-e "/^pidfile .*/c  pidfile /apps/redis/run/redis_6379.pid" \
-e '/# cluster-enabled yes/a cluster-enabled yes' \
-e '/# cluster-config-file nodes-6379.conf/a cluster-config-file /apps/redis/etc/nodes-6379.conf' \
-e '/cluster-require-full-coverage yes/a cluster-require-full-coverage no' \
/apps/redis/etc/redis.conf

# 启动服务
systemctl daemon-reload
systemctl enable --now redis

# 三个节点不创建 slave 节点
redis-cli -a alopex --cluster create 192.168.100.102:6379 192.168.100.103:6379 192.168.100.104:6379

// 集群(cluster)  
CLUSTER INFO                                打印集群的状态信息  
CLUSTER NODES                               列出集群当前已知的所有节点（node），以及这些节点的相关信息 

// 节点(node)  
CLUSTER MEET <ip> <port>                    将ip和port所指定的节点添加到集群当中，让它成为集群的一份子
CLUSTER FORGET <node_id>                    从集群中移除node_id指定的节点
CLUSTER REPLICATE <node_id>                 将当前节点设置为node_id指定节点的从节点
CLUSTER SAVECONFIG                          将当前节点的配置信息手动保存到硬盘（nodes-port.conf） 
CLUSTER SLAVES <master_node_id>             查询指定的master_node_id主节点有哪些从（slave）节点

// 槽(slot)  
CLUSTER ADDSLOTS <slot> [slot ...]          将一个或多个槽（slot）指派（assign）给当前节点
CLUSTER DELSLOTS <slot> [slot ...]          将一个或多个槽从当前节点移除
CLUSTER FLUSHSLOTS                          移除指派给当前节点的所有槽，让当前节点变成一个没有指派任何槽的节点
CLUSTER SETSLOT <slot> NODE <node_id>       将当前节点指定的槽（slot）指派给node_id指定的节点，如果槽已经指派给另一个节点，那么先让另一个节点删除该槽，然后再进行指派
CLUSTER SETSLOT <slot> MIGRATING <node_id>  将当前节点指定的槽（slot）迁移到node_id指定的节点中
CLUSTER SETSLOT <slot> IMPORTING <node_id>  从node_id指定节点中的槽（slot）导入到当前节点
CLUSTER SETSLOT <slot> STABLE               取消对当前节点指定槽（slot）的导入（import）或者迁移（migrate）
CLUSTER SLOTS                               查看槽（slot）在集群中的分配情况

// 键 (key)  
CLUSTER KEYSLOT <key>                       计算键key应该被分配在哪个槽上  
CLUSTER COUNTKEYSINSLOT <slot>              返回指定槽（slot）保存key的数量  
CLUSTER GETKEYSINSLOT <slot> <count>        获取指定槽（slot）中count个key，如果指定槽中大于count个key，则只返回前cout个key，小于或为空，则返回最多数量的key