shell学习

1. 获取IP地址

#/bin/bash
ipAddr=$(ip addr show | grep inet | grep -v inet6 | grep '/24' | awk '{print $2}' | awk -F '/' '{print $1}')
echo "网卡IP地址：${ipAddr}"

2. 检测某域名、IP地址是否通

#!/bin/bash
targetAddr=$1
if [ $1 ] &&  ( ping -c 2 ${targetAddr} &>/dev/null ); then
        echo "${targetAddr}通"
else 
        echo '目标地址空或者目标地址访问不通，请检查'
fi

3. 防火墙开闭端口、查看端口开闭状态、所有对外开放的端口

#!/bin/bash


# 开启端口
openPort () {
        if [ ! $1 ]; then
                echo '请输入需要开启的端口，请检查'
                exit 1
        fi
        portStatus=$(firewall-cmd --query-port="$1"/tcp)
        if [ $portStatus = 'no' ]; then
                sudo firewall-cmd --add-port=$1/tcp --permanent
                firewall-cmd --reload
                sleep 1s
                echo "端口【$1】已成功开启"
        else 
                echo "端口【$1】已开启，无需重复开启"
        fi
}

# 关闭端口
closePort () {
        if [ ! $1 ]; then
                echo "请输入需要关闭的端口，请检查"
                exit 1
        fi
        portStatus=$(firewall-cmd --query-port="$1"/tcp)
        if [ $portStatus = 'yes' ]; then
                firewall-cmd --permanent --remove-port=$1/tcp
                firewall-cmd --reload
                sleep 1s
                echo "端口【$1】已成功关闭"
        else
                echo "端口【$1】已关闭，无需重复关闭"
        fi
}

# 查看端口是否开启关闭
checkPort () {
        if [ ! $1 ]; then
                echo '请输入需要检查的端口，请检查'
                exit 1
        fi
        portStatus=$(firewall-cmd --query-port="$1"/tcp)
        echo "端口【$1】状态：$portStatus"
}

# 查看系统中开放的端口
listPort () {
        openPortInfo=$( firewall-cmd --list-all | grep ports | awk  'NR==1{for(i=2;i<=NF;i++) print $i}'  | sort -nk 1 -t '/')
        echo "系统中对外开启的端口"
        echo "$openPortInfo"
}


case $1 in
open)
        openPort $2
        ;;
close)
        closePort $2
        ;;
check|status)
        checkPort $2
        ;;
list)
        listPort
        ;;
*)
        echo '参数错误：请输入第一个参数open|close|check|status|list 中的任何一个、第二个参数【可选】端口号' 
esac

sh firewallUtil.sh open 端口号
sh firewallUtil.sh close 端口号
sh firewallUtil.sh check 端口号
sh firewallUtil.sh list

4. Nginx安装脚本

#!/bin/bash

# 检查是否是root用户,不是则退出程序；检查是否有wget应用,没有则帮其装上
# 如果已经安装且启动的，想重新安装，自行手动杀死后台的Nginx进程  
check () {
  test $USER == 'root' || (echo '必须是root用户，请检查' ; exit 1)
   [ -e /usr/bin/wget ] || yum -y install wget &>/dev/null 
}

# 依赖安装
install_dependencies () {
  if ! ( yum -y install elinks gcc-* pcre-devel zlib-devel 1>/dev/null ); then
    echo "nginx相关的依赖安装失败，请检查"
    exit 1
  fi
}


# 变量分别是
#   nginx_home：下载目录[别将其设为根目录，会导致删掉整个Linux，后果自负]
#   nginx_install_home：安装目录[别将其设为根目录，会导致删掉整个Linux，后果自负]
#   nginx_version：Nginx版本号
nginx_home=/usr/nginx
nginx_install_home=/usr/nginx/nginx
nginx_version=nginx-1.20.0.tar.gz

# 下载、解压nginx
download_nginx () {
        if [ ! -d ${nginx_home} ]; then
          mkdir -p ${nginx_home}
        fi
        
        cd $nginx_home
        rm -rf *

        # if ! $(find / -name $nginx_version | grep  ${nginx_home}'/'$nginx_version); then 
        rm -rf ${nginx_version}
        wget "http://nginx.org/download/${nginx_version}" || (echo "nginx安装包下载失败, 请检查" ; exit 1)
        # fi

        tar -xvf ${nginx_version} 1>/dev/null || echo " ${nginx_version}解压失败"
        
}

# 安装nginx
install_nginx () {
  cd $(echo $nginx_version | cut -d '.' -f1-3)
  rm -rf ${nginx_install_home}
  if ./configure --prefix=${nginx_install_home} 1>/dev/null; then
    echo "Nginx: 配置成功"
    if make 1>/dev/null; then
       echo "Nginx: 编译成功"
       if make install 1>/dev/null; then
         echo "Nginx: 编译后安装成功"
       else 
         echo "Nginx: 编译后安装失败"
         make clean
         exit 1
       fi
    else 
       echo "Nginx: 编译失败"
       make clean
       exit 1
    fi
  else  
    echo "Nginx: 配置失败"
    exit 1 
  fi
}

# 启动nginx
test_nginx () {
 if $nginx_install_home/sbin/nginx ; then 
   # 将nginx设为全局命令
   ln -s $nginx_install_home/sbin/nginx /usr/bin/nginx
   echo "Nginx: 启动成功"
   # 访问80端口，查看是否是nginx页面
   elinks http://localhost -dump
   nginx -v
 else
   echo "Nginx: 启动失败"
 fi
}

# 开放服务器防火墙80端口给外界
open_firewalld_80 () {
  # 查看Linux防火墙是否开启，开启则开放80端口，否则不做处理
  if firewall-cmd --state | grep 'running' ; then
    firewall-cmd --permanent --add-port=80/tcp   
    firewall-cmd --reload
    echo '80端口已经开启，可通过浏览器进行访问服务器80端口'
  fi
}



# 调用上述函数, 开始执行Nginx安装流程
check
install_dependencies
download_nginx
install_nginx
test_nginx
open_firewalld_80

5. 监控磁盘IO

"

运行前安装iostat：yum -y install sysstat

"

#!/bin/bash



startIoStat () {
  echo "IO设备名  平均每秒写的数据量【KB】  平均每次IO请求等待的时间【毫秒】"
  # 每秒打印5次 iostat -x报告
  # 抓取vdx设备的数据
  iostat -x 1 5  | egrep '^vd[a-z]' | awk '{io_writeDataInfo[$1]+=$7;io_waitDataInfo[$1]+=$10;print $1,$7,$10}END{print "平均结果";for (elem in io_writeDataInfo ) print elem, io_writeDataInfo[elem]/5, io_waitDataInfo[elem]/5; print "=================" }'
}

case $1 in
one)
  startIoStat
  ;;
iterator)
  while [ true ]; do
     startIoStat
     sleep 5
  done
  ;;
*)
  startIoStat
  ;;
esac

6. 监控本机内存使用率

#!/bin/bash
totalMemory=$( head -9 /proc/meminfo | awk 'NR==1{print $2}')
usedMemory=$( head -9 /proc/meminfo | awk 'NR==9{print $2}')
freeMemory=$( head -9 /proc/meminfo | awk 'NR==2{print $2}')
cachedMemory=$( head -9 /proc/meminfo | awk 'NR==4{buffers=$2}NR==5{print buffers+$2}')

echo -e "usedMemoryRate: $(($usedMemory * 100 / $totalMemory)) %"
echo -e "cachedMemoryRate: $(($cachedMemory * 100 / $totalMemory)) %"
echo -e "freeMemoryRate: $(($freeMemory * 100 / $totalMemory)) %"

7. Dos攻击防范 ，收藏起来（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

8. 系统发送告警脚本

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

9. 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

10. 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

11. 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)

12. 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(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]++}END{for(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]++}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数量"
awk '{a[$7" "$9]++}END{for(v in a){if(a[v]>5)print v,a[v]}}'

13. 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

14. 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

15. 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