9 个实用的 Shell 脚本

好久没更新了，实在不知道写点什么好，就在网上找了一些资源。正文是杜老师整理的 9 个实用 Shell 脚本，供有需要的小伙伴参考。需要注意的是，这些脚本为杜老师收集，并没有测试过，小伙伴们使用之前要先测试。

写在最前

常来的小伙伴应该发现杜老师说近两周没有更新了，过年期间确实有太多的事情需要处理，各种亲戚走动等等。目前已经处理差不多了，工作上的节奏也已慢慢稳定，近期开始补上之前拖更文章。开头也祝愿来访的小伙伴们龙年大吉，博客访问蒸蒸日上，身体和服务器健健康康，心想和收入皆遂意！

DoS 攻击防范自动屏蔽攻击 IP

#!/bin/bash
DATE=$(date +%d/%b/%Y:%H:%M)
LOG_FILE=/usr/local/nginx/logs/demo2.access.log
ABNORMAL_IP=$(tail -n5000 $LOG_FILE | grep $DATE | awk '{a[$1]++}END{for(i in a)if(a[i]>10)print i}')
for IP in $ABNORMAL_IP; do
	if [ $(iptables -vnL | grep -c "$IP") -eq 0 ]; then
		iptables -I INPUT -s $IP -j DROP
		echo "$(date +'%F_%T') $IP" >>/tmp/drop_ip.log
	fi
done

Linux 系统发送告警邮件的脚本

# yum install mailx
# vi /etc/mail.rc
set from=baojingtongzhi@163.com smtp=smtp.163.com
set smtp-auth-user=baojingtongzhi@163.com smtp-auth-password=123456
set smtp-auth=login

MySQL 数据库的单循环备份

#!/bin/bash
DATE=$(date +%F_%H-%M-%S)
HOST=localhost
USER=backup
PASS=123.com
BACKUP_DIR=/data/db_backup
DB_LIST=$(mysql -h$HOST -u$USER -p$PASS -s -e "show databases;" 2>/dev/null | egrep -v "Database|information_schema|mysql|performance_schema|sys")

for DB in $DB_LIST; do
	BACKUP_NAME=$BACKUP_DIR/${DB}_${DATE}.sql
	if ! mysqldump -h$HOST -u$USER -p$PASS -B $DB >$BACKUP_NAME 2>/dev/null; then
		echo "$BACKUP_NAME 备份失败!"
	fi
done

MySQL 数据库的多循环备份

#!/bin/bash
DATE=$(date +%F_%H-%M-%S)
HOST=localhost
USER=backup
PASS=123.com
BACKUP_DIR=/data/db_backup
DB_LIST=$(mysql -h$HOST -u$USER -p$PASS -s -e "show databases;" 2>/dev/null | egrep -v "Database|information_schema|mysql|performance_schema|sys")

for DB in $DB_LIST; do
	BACKUP_DB_DIR=$BACKUP_DIR/${DB}_${DATE}
	[ ! -d $BACKUP_DB_DIR ] && mkdir -p $BACKUP_DB_DIR &>/dev/null
	TABLE_LIST=$(mysql -h$HOST -u$USER -p$PASS -s -e "use $DB;show tables;" 2>/dev/null)
	for TABLE in $TABLE_LIST; do
		BACKUP_NAME=$BACKUP_DB_DIR/${TABLE}.sql
		if ! mysqldump -h$HOST -u$USER -p$PASS $DB $TABLE >$BACKUP_NAME 2>/dev/null; then
			echo "$BACKUP_NAME 备份失败!"
		fi
	done
done

Nginx 的访问日志按天切割

#!/bin/bash
LOG_DIR=/usr/local/nginx/logs
YESTERDAY_TIME=$(date -d "yesterday" +%F)
LOG_MONTH_DIR=$LOG_DIR/$(date +"%Y-%m")
LOG_FILE_LIST="default.access.log"

for LOG_FILE in $LOG_FILE_LIST; do
	[ ! -d $LOG_MONTH_DIR ] && mkdir -p $LOG_MONTH_DIR
	mv $LOG_DIR/$LOG_FILE $LOG_MONTH_DIR/${LOG_FILE}_${YESTERDAY_TIME}
done

kill -USR1 $(cat /var/run/nginx.pid)

Nginx 访问日志的分析脚本

#!/bin/bash
#日志格式: $remote_addr - $remote_user [$time_local] "$request" $status $body_bytes_sent "$http_referer" "$http_user_agent" "$http_x_forwarded_for"
LOG_FILE=$1
echo "统计访问最多的 10 个 IP"
awk '{a[$1]++}END{print "UV:",length(a);for(v in a)print v,a[v]}' $LOG_FILE | sort -k2 -nr | head -10
echo "----------------------"

echo "统计时间段访问最多 IP"
awk '$4>="[01/Dec/2018:13:20:25" && $4<="[27/Nov/2018:16:20:49"{a[$1]++}END{for(v in a)print v,a[v]}' $LOG_FILE | sort -k2 -nr | head -10
echo "----------------------"

echo "统计访问最多 10 个页面"
awk '{a[$7]++}END{print "PV:",length(a);for(v in a){if(a[v]>10)print v,a[v]}}' $LOG_FILE | sort -k2 -nr
echo "----------------------"

echo "统计访问页面状态码的数量"
awk '{a[$7" "$9]++}END{for(v in a){if(a[v]>5)print v,a[v]}}'

查看网卡实时流量脚本

#!/bin/bash
NIC=$1
echo -e " In ------ Out"
while true; do
	OLD_IN=$(awk '$0~"'$NIC'"{print $2}' /proc/net/dev)
	OLD_OUT=$(awk '$0~"'$NIC'"{print $10}' /proc/net/dev)
	sleep 1
	NEW_IN=$(awk '$0~"'$NIC'"{print $2}' /proc/net/dev)
	NEW_OUT=$(awk '$0~"'$NIC'"{print $10}' /proc/net/dev)
	IN=$(printf "%.1f%s" "$((($NEW_IN - $OLD_IN) / 1024))" "KB/s")
	OUT=$(printf "%.1f%s" "$((($NEW_OUT - $OLD_OUT) / 1024))" "KB/s")
	echo "$IN $OUT"
	sleep 1
done

服务器系统配置初始化脚本

#/bin/bash
#设置时区同步时间
ln -s /usr/share/zoneinfo/Asia/Shanghai /etc/localtime
if ! crontab -l | grep ntpdate &>/dev/null; then
	(
		echo "* 1 * * * ntpdate time.windows.com >/dev/null 2>&1"
		crontab -l
	) | crontab
fi

#禁用 SELinux 防火墙
sed -i '/SELINUX/{s/permissive/disabled/}' /etc/selinux/config

#关闭各版本防火墙
if egrep "7.[0-9]" /etc/redhat-release &>/dev/null; then
	systemctl stop firewalld
	systemctl disable firewalld
elif egrep "6.[0-9]" /etc/redhat-release &>/dev/null; then
	service iptables stop
	chkconfig iptables off
fi

#历史命令显示操作时间
if ! grep HISTTIMEFORMAT /etc/bashrc; then
	echo 'export HISTTIMEFORMAT="%F %T `whoami` "' >>/etc/bashrc
fi

#SSH 的超时时间
if ! grep "TMOUT=600" /etc/profile &>/dev/null; then
	echo "export TMOUT=600" >>/etc/profile
fi

#禁止 root 的远程登录
sed -i 's/#PermitRootLogin yes/PermitRootLogin no/' /etc/ssh/sshd_config

#禁止定时任务发送邮件
sed -i 's/^MAILTO=root/MAILTO=""/' /etc/crontab

#设置最大打开的文件数
if ! grep "* soft nofile 65535" /etc/security/limits.conf &>/dev/null; then
	cat >>/etc/security/limits.conf <<EOF
    * soft nofile 65535
    * hard nofile 65535
EOF
fi

#系统内核优化
cat >>/etc/sysctl.conf <<EOF
net.ipv4.tcp_syncookies = 1
net.ipv4.tcp_max_tw_buckets = 20480
net.ipv4.tcp_max_syn_backlog = 20480
net.core.netdev_max_backlog = 262144
net.ipv4.tcp_fin_timeout = 20
EOF

#减少 Swap 的使用
echo "0" >/proc/sys/vm/swappiness

#安装系统性能分析工具
yum install gcc make autoconf vim sysstat net-tools iostat if

监控 100 台服务器磁盘利用率脚本

#!/bin/bash
HOST_INFO=host.info
for IP in $(awk '/^[^#]/{print $1}' $HOST_INFO); do
	USER=$(awk -v ip=$IP 'ip==$1{print $2}' $HOST_INFO)
	PORT=$(awk -v ip=$IP 'ip==$1{print $3}' $HOST_INFO)
	TMP_FILE=/tmp/disk.tmp
	ssh -p $PORT $USER@$IP 'df -h' >$TMP_FILE
	USE_RATE_LIST=$(awk 'BEGIN{OFS="="}/^\/dev/{print $NF,int($5)}' $TMP_FILE)
	for USE_RATE in $USE_RATE_LIST; do
		PART_NAME=${USE_RATE%=*}
		USE_RATE=${USE_RATE#*=}
		if [ $USE_RATE -ge 80 ]; then
			echo "Warning: $PART_NAME Partition usage $USE_RATE%!"
		fi
	done
done