一.服务器系统配置初始化
背景：新购买10台服务器并已安装linux操作
需求：
1）设置时区并同步时间
2）禁用selinux
3）清空防火墙默认策略
4）历史命令显示操作时间
5）禁止root远程登录
6）禁止定时任务发送邮件
7）设置最大打开文件数
8）减少Swap使用
9）系统内核参数优化
10）安装系统性能分析工具及其他
[root@shell ~]# mkdir shell_scripts
[root@shell ~]# cd shell_scripts/
[root@shell shell_scripts]# vim 1.sh
#!/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 's#SELINUX=enforcing#SELINUX=disabled#g' /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(按公司规定）
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_fin_timeout = 2
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_tw_recycle = 1
net.ipv4.tcp_syncookies = 1
net.ipv4.tcp_keepalive_time = 600
net.ipv4.ip_local_port_range = 4000 65000
net.ipv4.tcp_max_syn_backlog = 16384
net.ipv4.tcp_max_tw_buckets = 36000
net.ipv4.route.gc_timeout = 100
net.ipv4.tcp_syn_retries = 1
net.ipv4.tcp_synack_retries = 1
net.core.somaxconn = 16384
net.core.netdev_max_backlog = 16384
net.ipv4.tcp_max_orphans = 16384
net.ipv4.ip_forward = 1
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 -y gcc make autoconf vim sysstat net-tools iostat iotp lrzse
#如果有一些语法错误，可以先转换unix
[root@shell shell_scripts]# yum install -y dos2unix
[root@shell shell_scripts]# dos2unix 1.sh
[root@shell shell_scripts]# ./1.sh
[root@shell shell_scripts]# source /etc/profile
二.发送告警邮件
外部邮箱服务器
[root@shell shell_scripts]# yum install mailx -y
[root@shell shell_scripts]# vim /etc/mail.rc
... ...末尾添加
set from=cdaneee@163.com smtp=smtp.163.com
set smtp-auth-user=cdaneee@163.com smtp-auth-password=caodan20!
set smtp-auth=login
[root@shell shell_scripts]# echo "this is test mail."|mail -s "monitor" 757294876@qq.com
三.批量创建100个用户并设置密码
[root@shell shell_scripts]# cat 3.sh
#!/bin/bash
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 sucessful!"
else
echo "$USER User already exists!"
fi
done
[root@shell shell_scripts]# sh 3.sh zhangsan lisi
Changing password for user zhangsan.
passwd: all authentication tokens updated successfully.
zhangsan User create sucessful!
Changing password for user lisi.
passwd: all authentication tokens updated successfully.
lisi User create sucessful!
[root@shell shell_scripts]# sh 3.sh zhangsan lisi
zhangsan User already exists!
lisi User already exists!
四.一键查看服务器利用率
cpu,内存，硬盘，tcp连接状态，
[root@shell shell_scripts]# cat 4.sh
#!/bin/bash
function cpu() {
util=$(vmstat |awk '{if(NR==3)print $13+$14}')
iowait=$(vmstat |awk '{if(NR==3)print $16}')
echo "CPU-使用率:${util}%,等待磁盘IO响应使用率:${iowait}%"
}
function memory() {
total=$(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:${total}G,已使用:${used}G,剩余:${available}G"
}
disk() {
fs=$(df -h |awk '/^\/dev/{print $1}')
for p in $fs; do
mounted=$(df -h |awk -v p=$p '$1==p{print $NF}')
size=$(df -h |awk -v p=$p '$1==p{print $2}')
used=$(df -h |awk -v p=$p '$1==p{print $3}')
used_percent=$(df -h |awk -v p=$p '$1==p{print $5}')
echo "硬盘-挂载点:$mounted,总大小:$size,已使用:$used,使用率:$used_percent"
done
}
tcp_status() {
summary=$(netstat -antp |awk '{a[$6]++}END{for(i in a)printf i":"a[i]" "}')
echo "TCP连接状态-$summary"
}
cpu
memory
disk
tcp_status
[root@shell shell_scripts]# chmod +x 4.sh
[root@shell shell_scripts]# sh 4.sh
CPU-使用率:2%,等待磁盘IO响应使用率:0%
内存-总大小:1.9G,已使用:1.2G,剩余:0.7G
硬盘-挂载点:/,总大小:18G,已使用:12G,使用率:64%
硬盘-挂载点:/home,总大小:1014M,已使用:33M,使用率:4%
TCP连接状态-LISTEN:11 ESTABLISHED:2 established):1 Foreign:1