!/bin/bash
################################

Author: xgmin

## Version: 1.0
## Date:    20191121
################################

yum clean all && yum repolist
yum install vim tree -y
#安装keepalived#####################
mkdir -p /etc/keepalived/script
mkdir -p /var/log/keepalived
#增加keepalived主从切换脚本#########
tee > /etc/keepalived/script/pgsql_check.sh <<'EOF'

#!/bin/bash
VIP=ip a | grep 10.10.10.247 | wc -l
#判断是否是从库处于等待的状态
Standby_Wait=ps -ef | grep postgres | grep 'startup process' | wc -l
#判断从库链接主库是否正常
Standby_Primary=ps -ef | grep postgres | grep 'receiver' | wc -l
#判断主库连接从库是否正常
Primary_Standby=ps -ef | grep postgres | grep 'sender' | wc -l
#如果pgstgresql端口号不存在，将消息写入日志并且关闭keepalived
if [ $(netstat -lntup | grep 5432 | wc -l) -eq 0 ]; then
echo "[$(date +"%F %T")] postgresql stop so vip stop" >> /var/log/keepalived/check_pg.log
systemctl stop keepalived

else
#判断出主挂了，vip浮到了从，提升从的地位让他可读写
if [ $VIP -eq 1 ] && [ $Standby_Wait -eq 1 ] && [ $Standby_Primary -eq 0 ]; then
su - postgres -c "pg_ctl promote -D /var/lib/pgsql/9.6/data/"
    echo "[$(date +"%F %T")] standby promote" >> /var/log/keepalived/check_pg.log
fi
#判断出自己是主并且和从失去联系
if [ $VIP -eq 1 ] && [ $Standby_Wait -eq 0 ] && [ $Standby_Primary -eq 0 ] && [ $Primary_Standby -eq 0 ]; then
sleep 5 && echo "[$(date +"%F %T")] can not find standby" >> /var/log/keepalived/check_pg.log
fi
fi
EOF
sleep 3
chmod +x /etc/keepalived/script/pgsql_check.sh
yum install keepalived -y
#修改keepalived配置文件#############
tee > /etc/keepalived/keepalived.conf <<'EOF'
! Configuration File for keepalived

global_defs {
router_id PRO_PGSQL
}

vrrp_script chk_pgsql_proxy {
script "/etc/keepalived/script/pgsql_check.sh"
interval 2
weight -20
}

vrrp_instance VI_1 {
state BACKUP
interface eth0
virtual_router_id 90
priority 200
advert_int 1
nopreempt
authentication {
auth_type PASS
auth_pass 363747
}
virtual_ipaddress {
10.10.10..247/24 dev eth0 label eth0:vip
}
track_script {
chk_pgsql_proxy
}
}
EOF
#修改keepalived日志#################
sed -i '14 s#KEEPALIVED_OPTIONS="-D"#KEEPALIVED_OPTIONS="-D -d -S 0"#g' /etc/sysconfig/keepalived
sed -i '1 i/var/log/keepalived/keepalived.log' /etc/logrotate.d/syslog
sed -i '42 i# keepalived' /etc/rsyslog.conf
sed -i '43 ilocal0. /var/log/keepalived/keepalived.log' /etc/rsyslog.conf
sed -i '44 i.err;kern.debug;daemon.notice;local0.none /var/log/messages' /etc/rsyslog.conf
sed -i '45 i\ ' /etc/rsyslog.conf
systemctl restart rsyslog