2. #!/bin/bash
    4. #设置时区并同步时间
    6. ln -s /usr/share/zoneinfo/Asia/Shanghai /etc/localtime
    8. if ! crontab -l |grep ntpdate &>/dev/null ; then
    10. (echo "* 1 * * * ntpdate time.windows.com >/dev/null 2>&1";crontab -l) |crontab
    12. fi
    14. #禁用selinux
    16. sed -i '/SELINUX/{s/enforcing/disabled/}' /etc/selinux/config
    18. #安装命令补全包
    20. yum install -y epel-release &>/dev/null 2>&1
    22. yum install -y bash-completion &>/dev/null 2>&1
    24. #清空firewall防火墙原来所有的规则,只保留ssh
    26. cd /etc/firewalld/zones/
    28. echo "" > public.xml
    30. cat >> public.xml << EOF
    32. Public
    34. EOF
    36. firewall-cmd --reload >/dev/null 2>&1
    38. #历史命令显示操作时间
    40. if ! grep HISTTIMEFORMAT /etc/bashrc; then
    42. echo 'export HISTTIMEFORMAT="%F %T whoami "' >> /etc/bashrc
    44. fi
    46. #SSH超时时间
    48. if ! grep "TMOUT=600" /etc/profile &>/dev/null; then
    50. echo "export TMOUT=600" >> /etc/profile
    52. fi
    54. #添加一个同root一样的超级用户，并禁止root远程登录
    56. NEW_USER=admin
    58. useradd $NEW_USER
    60. echo 123456 |passwd --stdin $NEW_USER
    62. #NEW_USER_ID=`cat /etc/passwd | grep $NEW_USER | awk -F ":" '{print $3}'`
    64. #CHANGE=\$s/$NEW_USER_ID/0/
    66. #sed -i "$CHANGE" /etc/passwd
    68. sed -i "92a $NEW_USER ALL=(ALL) NOPASSWD:ALL" /etc/sudoers
    70. sed -i 's/#PermitRootLogin yes/PermitRootLogin no/' /etc/ssh/sshd_config
    72. systemctl restart sshd
    74. #禁止定时任务向发送邮件
    76. sed -i 's/^MAILTO=root/MAILTO=""/' /etc/crontab
    78. #设置最大打开文件数
    80. if ! grep "* soft nofile 65535" /etc/security/limits.conf &>/dev/null; then
    82. cat >> /etc/security/limits.conf << EOF
    84. * soft nofile 65535
    86. * hard nofile 65535
    88. EOF
    90. fi
    92. #系统内核优化
    94. cat >> /etc/sysctl.conf << EOF
    96. net.ipv4.tcp_syncookies = 1
    98. net.ipv4.tcp_max_tw_buckets = 20480
    100. net.ipv4.tcp_max_syn_backlog = 20480
    102. net.core.netdev_max_backlog = 262144
    104. net.ipv4.tcp_fin_timeout = 20
    106. EOF
    108. #减少SWAP使用
    110. echo "0" > /proc/sys/vm/swappiness
    112. #安装系统性能分析工具及其他
    113. yum -y install gcc make autoconf vim sysstat net-tools iostat iftop iotp lrzsz &>/dev/null 2>&1