mechanism
Triggered during SSH connection/etc/pam.d/login, run the**motd**Set, will/etc/update-motd.d/Run all the scripts under the directory
pam.d
(Pluggable Authentication Modules)The verification module can be loaded dynamically
Learning summary of PAM module under Linux
Simply put, in/etc/pam.d/A verification module can be placed under the path, and the required service can be called. The file name of the verification module is the name of the service
Called during SSH login/etc/pam.d/login, where the following part callsMotd.
# Prints the message of the day upon successful login.
# (Replaces the `MOTD_FILE' option in login.defs)
# This includes a dynamically generated part from /run/motd.dynamic
# and a static (admin-editable) part from /etc/motd.
session optional pam_motd.so motd=/run/motd.dynamic
session optional pam_motd.so noupdateMotd (message of today)
Today’s news section provides various information on the welcome page Path is/etc/update-motd.d/, loginEach script under the path is run once
/etc/update-motd.d# ls
00-header 50-landscape-sysinfo 85-fwupd 90-updates-available 91-release-upgrade 95-hwe-eol 98-fsck-at-reboot
10-help-text 50-motd-news 88-esm-announce 91-contract-ua-esm-status 92-unattended-upgrades 97-overlayroot 98-reboot-requiredModify or add a script to modify welcome message
You can also create one/etc/motdFill in the document with the information you want to display The contents of this file will be displayed at the end of all the above scripts
Individual case
Ubuntu installed on the server purchased by Tencent cloud displays a welcome message when entering, but there is no prompt to update the package Running apt list – upgradable has many packages that can be updated Found after inspection/etc/update-motd.d/Script No. 90 is missing under the path90-updates-available, the update package message appears after you copy from other servers and add runnable permissions
Do not display welcome message
If you don’t want to display any welcome messages, there’s another way to change the script above It is to create a blank in the account directory hushlogin
~: touch .hushloginconnect
Where does the “n packages can be upgraded” message come from