[07-Sept-2020] A linux pam update arrived in August 2020: pam-1.4.x and pambase 20200721.x. This update changes the /etc/pam.d/system-login and might cause conflicts with changes by the steps below. This protentially prevents user login (affecting sudo and su too) after update. Make sure you back up the /etc/pam.d/system-login before making changes and check it after the pam 1.4.x update has been applied to your system
Pretty self explanatory. It works for Arch linux on:
- x86_64 machines (Intel/AMD based)
- ARM based machines (Raspberry Pi)
It will auto detect which architecture your system is and work accordingly.
Currently it can only display temperatures for Raspberry Pi, but using the lm_sensors package this could be done.
The MOTD is usually displayed when a user logs into the system (via KB and mouse or ssh or other means). The Linux PAM config specifies the when to display the MOTD.
The generate_motd.sh script executes on user login to output to the motd. Then at the "display motd" step of user login the new generated output is displayed. - This is what makes the motd dynamic.
Once installed, log in to your system and the script will update your /etc/motd with system data.
This happens before the user is given a prompt and after successful login.
Please Note: Editing the PAM configuration can be dangerous and will break your system if done incorrectly. It is recommended to back up before making changes otherwise you may not be able to log into your system again.
- Install the
generate_motd.shin/bin/directory - Give the script the same permissions as any other app in
/bin(run as root or sudo):chmod 0755 /bin/generate_motd.sh - Make sure the script has the correct ownership:
chown root:root /bin/generate_motd.sh - Update the
system-loginpam config file to execute the script before displaying themotd
The below changes will affect all logins (local, ssh etc.) If you wish to do just ssh, then do something different. Please understand what changes your are making and their impact before you do it
In the file: /etc/pam.d/system-login add the new line.
Go from this:
session include system-auth
session optional pam_motd.so motd=/etc/motd
To this:
session include system-auth
session optional pam_exec.so /bin/generate_motd.sh
session optional pam_motd.so motd=/etc/motd
Please Note: Check these settings against the Linux PAM manual and be aware of changes you are making mean for your system.
Information about linux PAM can be found here:
- https://dzone.com/articles/linux-pam-easy-guide
- https://linux.die.net/man/8/pam
- https://linux.die.net/man/5/pam.d
- https://wiki.archlinux.org/index.php/PAM
- Temperature for x86_64 (Intel/AMD) based machines
- Partition usage (similar to memory usage) that's dynamically detected
- Swap usage (similar to memory usage)
This motd generator for Arch Linux has been adapted from github user lfelipe1501's motd generator. This is the original code that I have adapted my version from: https://github.com/lfelipe1501/Arch-MOTD