linux系统 - 常用脚本 - 《运维笔记》

IP地址提取
systemd服务自动重启
ubuntu网卡配置
Ubuntu源地址
系统初始化
磁盘监控
邮件告警
批量创建用户
history命令添加时间及记录到syslog日志

IP地址提取

ip a | grep 'global' |awk '{print $2}' |awk -F / '{print $1}'

systemd服务自动重启

[Unit]
Description=ROT13 demo service
After=network.target
StartLimitIntervalSec=0    //自动重启限制间隔多少秒

[Service]
Type=simple
Restart=always             //自动重启
RestartSec=1               //多少秒后重新启动
User=ltpc
ExecStart=/usr/bin/env php /path/to/server.php

[Install]
WantedBy=multi-user.target

ubuntu网卡配置

vim /etc/netplan/

network:
  version: 2
  renderer: networkd
  ethernets:
    ens33:   #配置的网卡名称
      dhcp4: no    #dhcp4关闭
      dhcp6: no    #dhcp6关闭
      addresses: [192.168.1.55/24]   #设置本机IP及掩码
      gateway4: 192.168.1.254   #设置网关
      nameservers:
          addresses: [114.114.114.114, 8.8.8.8]   #设置DNS



 应用新配置
ubuntu1804:~$ sudo netplan apply

Ubuntu源地址

http://mirrors.aliyun.com/ubuntu/

系统初始化

#/bin/bash
#设置时区并同步时间
#禁用selinux
#清空防火墙默认策略
#历史命令显示操作时间
#禁止root远程登录
#禁止定时任务发送邮件
#设置最大打开文件数
#减少swap使用
#系统内核参数优化
#安装性能分析工具及其他


#设置时区并同步时间 cn.pool.ntp.org/time.windows.com
# cat /usr/share/zoneinfo/Asia/Shanghai >/etc/localtime
cd /etc
rm -f localtime
ln -s /usr/share/zoneinfo/Asia/Shanghai /etc/localtime
if ! crontab -l |grep ntpdate &>/dev/null ;then
    (echo "* 1 * * * ntpdate cn.pool.ntp.org >/dev/null 2>&1";crontab -l) |crontab
fi


#关闭selinux
sed -i '/SELINUX/{s/permissive/disabled}' /etc/selinux/config


#开启防火墙并设置防火墙规则/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

#系统内核优化

cat >> /etc/sysctl.conf << EOF
net.ipv4.tcp_max_tw_buckets = 6000
net.ipv4.tcp_sack = 1
net.ipv4.tcp_window_scaling = 1
net.ipv4.tcp_rmem = 4096 87380 4194304
net.ipv4.tcp_wmem = 4096 16384 4194304
net.core.wmem_default = 8388608
net.core.rmem_default = 8388608
net.core.rmem_max = 16777216
net.core.wmem_max = 16777216
net.core.netdev_max_backlog = 262144
net.core.somaxconn = 262144
net.ipv4.tcp_max_orphans = 3276800
net.ipv4.tcp_max_syn_backlog = 262144
net.ipv4.tcp_timestamps = 0
net.ipv4.tcp_synack_retries = 1
net.ipv4.tcp_syn_retries = 1
net.ipv4.tcp_tw_recycle = 1
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_mem = 94500000 915000000 927000000
net.ipv4.tcp_fin_timeout = 1
net.ipv4.tcp_keepalive_time = 30
net.ipv4.ip_local_port_range = 1024 65000
net.nf_conntrack_max = 655360
net.netfilter.nf_conntrack_tcp_timeout_established = 1200


#防火墙优化，不开防火墙不用做如下操作
net.nf_conntrack_max = 25000000
net.netfilter.nf_conntrack_max = 25000000
net.netfilter.nf_conntrack_tcp_timeout_established = 180
net.netfilter.nf_conntrack_tcp_timeout_time_wait = 120
net.netfilter.nf_conntrack_tcp_timeout_close_wait = 60
net.netfilter.nf_conntrack_tcp_timeout_fin_wait = 120
EOF
sysctl -p /etc/sysctl.conf
#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 -y install gcc make autoconf vim sysstat net-tools iostat iftop iotp lrzsz

磁盘监控

#!/bin/bash

function cpu() {
    NUM=1
    while [ $NUM -le 3 ]; do
        util=`vmstat |awk '{if(NR==3)print 100-$15"%"}'`
        user=`vmstat |awk '{if(NR==3)print $13"%"}'`
        sys=`vmstat |awk '{if(NR==3)print $14"%"}'`
        iowait=`vmstat |awk '{if(NR==3)print $16"%"}'`
        echo "CPU - 使用率: $util , 等待磁盘IO响应使用率: $iowait"
        let NUM++
        sleep 1
    done
}

function memory() {
    total=`free -m |awk '{if(NR==2)printf "%.1f",$2/1024}'`
    used=`free -m |awk '{if(NR==2) printf "%.1f",($2-$NF)/1024}'`
    available=`free -m |awk '{if(NR==2) printf "%.1f",$NF/1024}'`
    echo "内存 - 总大小: ${total}G , 使用: ${used}G , 剩余: ${available}G"
}

function disk() {
    fs=$(df -h |awk '/^\/dev/{print $1}')
    for p in $fs; do
        mounted=$(df -h |awk '$1=="'$p'"{print $NF}')
        size=$(df -h |awk '$1=="'$p'"{print $2}')
        used=$(df -h |awk '$1=="'$p'"{print $3}')
        used_percent=$(df -h |awk '$1=="'$p'"{print $5}')
        echo "硬盘 - 挂载点: $mounted , 总大小: $size , 使用: $used , 使用率: $used_percent"
    done
}

function tcp_status() {
    summary=$(ss -antp |awk '{status[$1]++}END{for(i in status) printf i":"status[i]" "}')
    echo "TCP连接状态 - $summary"
}

cpu
memory
disk
tcp_status

邮件告警

# /bin/bash
#
#邮件告警
#邮件告警注意云服务器需要开启邮箱所需要的端口，如果使用https，还要设置证书，http与https端口不一致

yum -y install mailx

# /etc/mail.rc
echo "set from=18816487279@163.com smtp=smtp.163.com" >> /etc/mail.rc
echo "set smtp-auth-user=18816487279@163.com smtp-auth-password=roes123" >> /etc/mail.rc
echo "set smtp-auth=login" >> /etc/mail.rc

批量创建用户

#/bin/bash
#批量创建用户
#执行脚本，并在脚本后面添加用户名

USER_LIST=$@
USER_FILE=./user.info
for USER in $USER_LIST;do
    if ! id $USER &>/dev/null;then
        PASS=$(echo $RANDOM |md5sum |cut -c 1-8)
        useradd $USER
        echo $PASS | passwd --stdin $USER $>/dev/null
        echo "$USER $PASS" >> $USER_FILE
        echo "$USER USER create successful"
    else
        echo "$USER USER already exists!"
    fi
done

history命令添加时间及记录到syslog日志

history记录中添加时间，用户地址等信息
vi /etc/profile
export HISTTIMEFORMAT=" %F %T `who -u am i 2> /dev/null | awk '{print $NF}' | sed -e 's/[()]//g'` `whoami` "

history记录添加到 syslog日志
vi /etc/profile
export PROMPT_COMMAND=' history -a >(tee -a ~/.bash_history | logger -t "$USER[$$] $SSH_CONNECTION") '

source /etc/profile

磁盘读写测试

#!/bin/bash

echo "顺序读写"
fio -direct=1  -iodepth=64  -rw=read -ioengine=psync -bs=16k -size=1G -numjobs=10 -runtime=100 -group_reporting -name=/data/iotest|grep 'read: IOPS='
fio -direct=1  -iodepth=64  -rw=write -ioengine=psync -bs=16k -size=1G -numjobs=10 -runtime=100 -group_reporting -name=/data/iotest|egrep 'write: IOPS'

echo "随机读写"
fio -direct=1  -iodepth=64  -rw=randread -ioengine=psync -bs=16k -size=1G -numjobs=10 -runtime=100 -group_reporting -name=/data/iotest |grep 'read: IOPS='
fio -direct=1  -iodepth=64  -rw=randwrite -ioengine=psync -bs=16k -size=1G -numjobs=10 -runtime=100 -group_reporting -name=/data/iotest|egrep 'write: IOPS'