--- layout: single title: "SSH 登录欢迎信息" date: 2021-04-09 00:00:00 +0800 categories: [容器与云原生, 操作系统] tags: [ssh, motd, Login, Linux, Welcome] --- 终端登录时显示给用户的欢迎消息，无论是通过远程 SSH 登录还是直接通过 TTY 或终端，是 ```motd``` 的一部分，即 ```Message Of The Day``` 守护程序。 通过修改 ```/etc/update-motd.d``` 目录中的 ```/etc/motd``` 文件或脚本，可以自定义 motd 消息以适合每个用户或管理员的个性化需求。 ## 附加 motd 消息 ```shell sudo sh -c 'echo "Hello World!" > /etc/motd' ``` 退出后重新登录 ```shell $ ssh username@hostname Welcome to Ubuntu 20.04 LTS (GNU/Linux 5.4.0-53-generic x86_64) * Documentation: https://help.ubuntu.com * Management: https://landscape.canonical.com * Support: https://ubuntu.com/advantage System information as of Thu 29 Apr 2021 08:16:49 AM UTC System load: 7.85 Processes: 1046 Usage of /: 62.1% of 548.61GB Users logged in: 2 Memory usage: 32% IPv4 address for docker0: 172.17.0.1 Swap usage: 0% IPv4 address for ens4f0: 172.16.33.66 Temperature: 52.0 C IPv4 address for weave: 10.46.0.0 => There are 16 zombie processes. * Pure upstream Kubernetes 1.21, smallest, simplest cluster ops! https://microk8s.io/ 128 updates can be installed immediately. 0 of these updates are security updates. To see these additional updates run: apt list --upgradable *** System restart required *** Hello World! Last login: Thu Apr 29 07:55:59 2021 from 192.168.73.141 ``` ## 修改 motd 消息 可以通过 ```/etc/update-motd.d``` 目录下的脚本自定义。motd 是模块化的，因此分为多个脚本，这些脚本按从最低编号到最高编号的顺序执行，作为脚本文件名前缀的一部分。每个脚本都分配有可执行权限。随意修改以上任何脚本，以使 motd 消息输出更好地适合您的系统环境。 ### /etc/update-motd.d/ 目录下的脚本 ``` /etc/update-motd.d/ ├── 00-header ├── 10-help-text ├── 50-landscape-sysinfo -> /usr/share/landscape/landscape-sysinfo.wrapper ├── 50-motd-news ├── 85-fwupd ├── 90-updates-available ├── 91-release-upgrade ├── 92-unattended-upgrades ├── 95-hwe-eol ├── 97-overlayroot ├── 98-fsck-at-reboot └── 98-reboot-required ``` ### 禁用所有脚本 ```shell sudo chmod -x /etc/update-motd.d/* ``` 退出后重新登录 ```shell $ ssh username@hostname Last login: Thu Apr 29 08:28:25 2021 from 192.168.73.141 ``` ### 启用 50-landscape-sysinfo ```shell sudo chmod +x /etc/update-motd.d/50-landscape-sysinfo ``` 退出后重新登录 ```shell $ ssh username@hostname System information as of Thu 29 Apr 2021 08:40:47 AM UTC System load: 8.34 Processes: 1057 Usage of /: 62.1% of 548.61GB Users logged in: 2 Memory usage: 32% IPv4 address for docker0: 172.17.0.1 Swap usage: 0% IPv4 address for ens4f0: 172.16.33.66 Temperature: 53.0 C IPv4 address for weave: 10.46.0.0 => There are 16 zombie processes. Last login: Thu Apr 29 08:36:48 2021 from 192.168.73.141 ``` ### 自定义显示本地天气 ```shell sudo apt install ansiweather sudo vim 99-location-weather ``` ```shell #!/bin/sh echo ansiweather -l Jinan ``` ```shell sudo chmod +x 99-location-weather ``` 退出后重新登录 ```shell $ ssh username@hostname System information as of Thu 29 Apr 2021 08:54:40 AM UTC System load: 7.95 Processes: 1035 Usage of /: 62.1% of 548.61GB Users logged in: 2 Memory usage: 32% IPv4 address for docker0: 172.17.0.1 Swap usage: 0% IPv4 address for ens4f0: 172.16.33.66 Temperature: 52.0 C IPv4 address for weave: 10.46.0.0 => There are 16 zombie processes. Weather in Jinan => 23 °C - Wind => 6.55 m/s NW - Humidity => 12 % - Pressure => 1001 hPa Last login: Thu Apr 29 08:48:59 2021 from 192.168.73.141 ``` ## 禁止显示最后登录信息 ```shell sudo vim /etc/ssh/sshd_config ``` 增加配置信息 ``` PrintLastLog no ``` 重启 ssh 服务 ```shell sudo /etc/init.d/ssh restart ``` 退出后重新登录 ```shell $ ssh username@hostname System information as of Thu 29 Apr 2021 08:54:40 AM UTC System load: 7.95 Processes: 1035 Usage of /: 62.1% of 548.61GB Users logged in: 2 Memory usage: 32% IPv4 address for docker0: 172.17.0.1 Swap usage: 0% IPv4 address for ens4f0: 172.16.33.66 Temperature: 52.0 C IPv4 address for weave: 10.46.0.0 => There are 16 zombie processes. ``` ## 用户登录后禁止显示所有消息 ```shell touch $HOME/.hushlogin ``` ## 参考资料 * [How to change welcome message (motd) on Ubuntu 18.04 server](https://linuxconfig.org/how-to-change-welcome-message-motd-on-ubuntu-18-04-server) * [How can I edit the welcome message when ssh start?](https://serverfault.com/questions/407033/how-can-i-edit-the-welcome-message-when-ssh-start) * [Change the Terminal Message of the Day in Mac OS X](https://osxdaily.com/2007/01/30/change-the-mac-os-x-terminals-message-of-the-day/)