ssh login prompt interface customization

ssh 登录欢迎界面如下：
Welcome to Ubuntu 14.04.1 LTS (GNU/Linux 3.13.0-37-generic x86_64)

* Documentation:  https://help.ubuntu.com/

  System information as of Fri Dec  4 19:27:24 CST 2015

  System load:  11.38               Processes:          435
  Usage of /:   76.3% of 517.82GB   Users logged in:    1
  Memory usage: 8%                  IP address for em1: 192.*.*.*
  Swap usage:   1%

  => /mnt/storage is using 89.6% of 1.79TB

  Graph this data and manage this system at:
    https://landscape.canonical.com/

Last login: Fri Dec  4 19:27:24 2015 from 192.*.*.*

------------------------------------------按下面操作就行---------------------------------------------------------------
$ cd /etc/update-motd.d/
$ls # 00-header can also be changed
00-header 50-landscape-sysinfo 91-release-upgrade 98-reboot-required
10-help-text 90-updates-available 98- fsck-at-reboot
$ vim 50-landscape-sysinfo
Adding this sentence /usr/bin/landscape-sysinfo
will display the following information;
  System load: 17.47 Processes: 392
  Usage of /: 76.3% of 517.82GB Users logged in: 1
  Memory usage: 9% IP address for em1: 192.*.*.*
  Swap usage: 1%

  => /mnt/storage is using 89.7% of 1.79TB

  Graph this data and manage this system at:
    https://landscape. canonical.com/
---------------That's it, you can know the general situation of the system when you log in ---------------- --------------------