22.2. 创建运行 dhclient exit hooks 的 NetworkManager 分配程序脚本

流程

1. 使用以下内容创建 /etc/NetworkManager/dispatcher.d/12-dhclient-down 文件：

   #!/bin/bash
   # Run dhclient.exit-hooks.d scripts
   
   if [ -n "$DHCP4_DHCP_LEASE_TIME" ] ; then
     if [ "$2" = "dhcp4-change" ] || [ "$2" = "up" ] ; then
       if [ -d /etc/dhcp/dhclient-exit-hooks.d ] ; then
         for f in /etc/dhcp/dhclient-exit-hooks.d/*.sh ; do
           if [ -x "${f}" ]; then
             . "${f}"
           fi
         done
       fi
     fi
   fi

2. 将 root 用户设为文件的所有者：

   # chown root:root /etc/NetworkManager/dispatcher.d/12-dhclient-down

3. 设置权限，以便只有 root 用户才能执行它：

   # chmod 0700 /etc/NetworkManager/dispatcher.d/12-dhclient-down

4. 恢复 SELinux 上下文：

   # restorecon /etc/NetworkManager/dispatcher.d/12-dhclient-down