9 个实用 Shell 脚本，建议收藏！

Posted 2022-10-19

1、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]++ENDfor(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

2.Linux 系统发送告警脚本

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

3.mysql 数据库备份单循环

#!/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

4.MySQL 数据库备份多循环

#!/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

5.Nginx 访问访问日志按天切割

#!/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)

6.Nginx 访问日志分析脚本

#!/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]++ENDprint "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的IP"
awk $4>="[01/Dec/2018:13:20:25" && $4<="[27/Nov/2018:16:20:49"a[$1]++ENDfor(v in a)print v,a[v] $LOG_FILE |sort -k2 -nr|head -10
echo "----------------------"

echo "统计访问最多的10个页面"
awk a[$7]++ENDprint "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数量"
awk a[$7" "$9]++ENDfor(v in a)if(a[v]>5)print v,a[v]

7.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

8.服务器系统配置初始化脚本

#/bin/bash
# 设置时区并同步时间
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
sed -i /SELINUX/s/permissive/disabled/ /etc/selinux/config
# 关闭防火墙
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超时时间
if ! grep "TMOUT=600" /etc/profile &>/dev/null; then
    echo "export TMOUT=600" >> /etc/profile
fi
# 禁止root远程登录
sed -i s/#PermitRootLogin yes/PermitRootLogin no/ /etc/ssh/sshd_config
# 禁止定时任务向发送邮件
sed -i s/^MAILTO=root/MAILTO=""/ /etc/crontab
# 设置最大打开文件数
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使用
echo "0" > /proc/sys/vm/swappiness
# 安装系统性能分析工具及其他
yum install gcc make autoconf vim sysstat net-tools iostat if

9.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==$1print $2 $HOST_INFO)
    PORT=$(awk -v ip=$IP ip==$1print $3 $HOST_INFO)
    TMP_FILE=/tmp/disk.tmp
    ssh -p $PORT $USER@$IP df -h > $TMP_FILE
    USE_RATE_LIST=$(awk BEGINOFS="="/^\\/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

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