9个常用的Shell脚本，面试也常问！
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[$1]++}END{for(iina)if(a[i]>10)printi}') forIPin$ABNORMAL_IP;do if[$(iptables-vnL|grep-c"$IP")-eq0];then iptables-IINPUT-s$IP-jDROP echo"$(date+'%F_%T')$IP">>/tmp/drop_ip.log fi done 2、Linux 系统发送告警脚本 #yuminstallmailx #vi/etc/mail.rc setfrom=baojingtongzhi@163.comsmtp=smtp.163.com setsmtp-auth-user=baojingtongzhi@163.comsmtp-auth-password=123456 setsmtp-auth=login 3、MySQL 数据库备份单循环 #!/bin/bash DATE=$(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"showdatabases;"2>/dev/null|egrep-v"Database|information_schema|mysql|performance_schema|sys") forDBin$DB_LIST;do BACKUP_NAME=$BACKUP_DIR/${DB}_${DATE}.sql if!mysqldump-h$HOST-u$USER-p$PASS-B$DB>$BACKUP_NAME2>/dev/null;then echo"$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$PASS-s-e"showdatabases;"2>/dev/null|egrep-v"Database|information_schema|mysql|performance_schema|sys") forDBin$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;showtables;"2>/dev/null) forTABLEin$TABLE_LIST;do BACKUP_NAME=$BACKUP_DB_DIR/${TABLE}.sql if!mysqldump-h$HOST-u$USER-p$PASS$DB$TABLE>$BACKUP_NAME2>/dev/null;then echo"$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/$(date+"%Y-%m") LOG_FILE_LIST="default.access.log" forLOG_FILEin$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[$1]++}END{print"UV:",length(a);for(vina)printv,a[v]}'$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[$1]++}END{for(vina)printv,a[v]}'$LOG_FILE|sort-k2-nr|head-10 echo"----------------------" echo"统计访问最多的10个页面" awk'{a[$7]++}END{print"PV:",length(a);for(vina){if(a[v]>10)printv,a[v]}}'$LOG_FILE|sort-k2-nr echo"----------------------" echo"统计访问页面状态码数量" awk'{a[$7""$9]++}END{for(vina){if(a[v]>5)printv,a[v]}}' 7、查看网卡实时流量脚本 #!/bin/bash NIC=$1 echo-e"In------Out" whiletrue;do OLD_IN=$(awk'$0~"'$NIC'"{print$2}'/proc/net/dev) OLD_OUT=$(awk'$0~"'$NIC'"{print$10}'/proc/net/dev) sleep1 NEW_IN=$(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$OUT" sleep1 done 8、服务器系统配置初始化脚本 #/bin/bash #设置时区并同步时间 ln-s/usr/share/zoneinfo/Asia/Shanghai/etc/localtime if!crontab-l|grepntpdate&>/dev/null;then (echo"*1***ntpdatetime.windows.com>/dev/null2>&1";crontab-l)|crontab fi #禁用selinux sed-i'/SELINUX/{s/permissive/disabled/}'/etc/selinux/config #关闭防火墙 ifegrep"7.[0-9]"/etc/redhat-release&>/dev/null;then systemctlstopfirewalld systemctldisablefirewalld elifegrep"6.[0-9]"/etc/redhat-release&>/dev/null;then serviceiptablesstop chkconfigiptablesoff fi #历史命令显示操作时间 if!grepHISTTIMEFORMAT/etc/bashrc;then echo'exportHISTTIMEFORMAT="%F%T`whoami`"'>>/etc/bashrc fi #SSH超时时间 if!grep"TMOUT=600"/etc/profile&>/dev/null;then echo"exportTMOUT=600">>/etc/profile fi #禁止root远程登录 sed-i's/#PermitRootLoginyes/PermitRootLoginno/'/etc/ssh/sshd_config #禁止定时任务向发送邮件 sed-i's/^MAILTO=root/MAILTO=""/'/etc/crontab #设置最大打开文件数 if!grep"*softnofile65535"/etc/security/limits.conf&>/dev/null;then cat>>/etc/security/limits.conf<<EOF *softnofile65535 *hardnofile65535 EOF fi #系统内核优化 cat>>/etc/sysctl.conf<<EOF net.ipv4.tcp_syncookies=1 net.ipv4.tcp_max_tw_buckets=20480 net.ipv4.tcp_max_syn_backlog=20480 net.core.netdev_max_backlog=262144 net.ipv4.tcp_fin_timeout=20 EOF #减少SWAP使用 echo"0">/proc/sys/vm/swappiness #安装系统性能分析工具及其他 yuminstallgccmakeautoconfvimsysstatnet-toolsiostatif 9、监控 100 台服务器磁盘利用率脚本 #!/bin/bash HOST_INFO=host.info forIPin$(awk'/^[^#]/{print$1}'$HOST_INFO);do USER=$(awk-vip=$IP'ip==$1{print$2}'$HOST_INFO) PORT=$(awk-vip=$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) forUSE_RATEin$USE_RATE_LIST;do PART_NAME=${USE_RATE%=*} USE_RATE=${USE_RATE#*=} if[$USE_RATE-ge80];then echo"Warning:$PART_NAMEPartitionusage$USE_RATE%!" fi done done
