禁用和设置 Ubuntu MoTD 消息
TL;DR
要关闭 MoTD 消息，有两种方式：
- 用户级：
touch .hushlogin - 系统级：
sudo chmod -x /etc/update-motd.d/*
介绍
当你通过 SSH 登录 Ubuntu 时，通常会看到这样的消息：
Welcome to Ubuntu 22.04.5 LTS (GNU/Linux 5.15.0-131-generic x86_64)
* Documentation: https://help.ubuntu.com
* Management: https://landscape.canonical.com
* Support: https://ubuntu.com/pro
System information as of Wed Feb 26 06:00:49 PM UTC 2025
System load: 37.87
Usage of /home: 52.2% of 6.15TB
Memory usage: 10%
Swap usage: 1%
Processes: 1958
Users logged in: 9
IPv4 address for enp1s0f0: 192.168.1.2
IPv6 address for enp1s0f0: f451:340:2001:58b4:8fc1:15fb:1e8c:18b9
* Strictly confined Kubernetes makes edge and IoT secure. Learn how MicroK8s
just raised the bar for easy, resilient and secure K8s cluster deployment.
https://ubuntu.com/engage/secure-kubernetes-at-the-edge
Expanded Security Maintenance for Applications is not enabled.
0 updates can be applied immediately.
24 additional security updates can be applied with ESM Apps.
Learn more about enabling ESM Apps service at https://ubuntu.com/esm
New release '24.04.2 LTS' available.
Run 'do-release-upgrade' to upgrade to it.
*** System restart required ***
这个东西叫 MoTD（Message of The Day），它允许系统管理员向用户显示公告。不过 Ubuntu 向其中加入了一些自己的东西，比如上面的这部分内容。有时候我们不想看到这些消息，或者只想看到消息的一部分。接下来介绍如何定制 MoTD。
MoTD News
在完整的 MoTD 中，有一小部分，叫 MoTD News，其内容如下：
* Strictly confined Kubernetes makes edge and IoT secure. Learn how MicroK8s
just raised the bar for easy, resilient and secure K8s cluster deployment.
https://ubuntu.com/engage/secure-kubernetes-at-the-edge
关闭 MoTD News 的方法很简单，只需要编辑 /etc/default/motd-news，并设置 ENABLED=0 即可。
动态 MoTD
在 /etc/update-motd.d 目录下有一堆脚本：
$ ls /etc/update-motd.d
00-header 90-updates-available 97-overlayroot
10-help-text 91-contract-ua-esm-status 98-fsck-at-reboot
50-landscape-sysinfo 91-release-upgrade 98-reboot-required
50-motd-news 92-unattended-upgrades
85-fwupd 95-hwe-eol
这些脚本控制了 MoTD 显示的内容。脚本名称前的序号表示它们显示的顺序。可以通过撤销执行权限来关闭显示：
sudo chmod -x 00-header
下面是各个文件负责显示的内容。
-
00-header:Welcome to Ubuntu 22.04.5 LTS (GNU/Linux 5.15.0-131-generic x86_64) -
10-help-text:* Documentation: https://help.ubuntu.com * Management: https://landscape.canonical.com * Support: https://ubuntu.com/pro -
50-landscape-sysinfo:System information as of Wed Feb 26 06:00:49 PM UTC 2025 System load: 37.87 Usage of /home: 52.2% of 6.15TB Memory usage: 10% Swap usage: 1% Processes: 1958 Users logged in: 9 IPv4 address for enp1s0f0: 192.168.1.2 IPv6 address for enp1s0f0: f451:340:2001:58b4:8fc1:15fb:1e8c:18b9 -
50-motd-news:和
/etc/default/motd-news一样，这个文件也可以控制 MoTD News 的显示。* Strictly confined Kubernetes makes edge and IoT secure. Learn how MicroK8s just raised the bar for easy, resilient and secure K8s cluster deployment. https://ubuntu.com/engage/secure-kubernetes-at-the-edge -
90-updates-available:Expanded Security Maintenance for Applications is not enabled. 0 updates can be applied immediately. 24 additional security updates can be applied with ESM Apps. Learn more about enabling ESM Apps service at https://ubuntu.com/esm -
91-release-upgrade:New release '24.04.2 LTS' available. Run 'do-release-upgrade' to upgrade to it. -
98-reboot-required:*** System restart required ***
静态 MoTD
管理员可以通过 /etc/motd 文件自定义用户登录系统时向用户显示的消息。
你可能会发现在设置了静态 MoTD 消息后，在登录时，MoTD 消息会显示两遍。这是因为 /etc/pam.d/sshd 和 /etc/ssh/sshd_config 都设置了是否显示 MoTD 消息。其中 SSH 显示的消息会出现在 SSH 登录记录的后面：
Last login: Wed Feb 26 18:37:59 2025 from 127.0.0.1
可以关闭其中之一来避免重复显示 MoTD 消息。
-
编辑
/etc/pam.d/sshd：注释掉下面两行（第一行控制动态 MoTD，第二行控制静态 MoTD）：
# session optional pam_motd.so motd=/run/motd.dynamic # session optional pam_motd.so noupdate -
编辑
/etc/ssh/sshd_config：将
PrintMotd设为no：PrintMotd no
参考：
浙公网安备 33010602011771号