The ask here is, when a logged-in user logs out of the ssh session, the system must execute a specific script or a command. So it is like configuring a post script or a trigger to perform the desired action when the user is logged out of the ssh session.
This can be easily done with the help of pam module in CentOS/RHEL systems. Follow the steps outlined below to configure the pam module.
1. Add the below entry to the pam configuration file /etc/pam.d/sshd:
# vi /etc/pam.d/sshd session optional pam_exec.so quiet /var/tmp/post_session.sh
/var/tmp/post_session.sh is our script which will run when the user is logged out.
The /etc/pam.d/sshd configuration file should look like below:
# cat /etc/pam.d/sshd #%PAM-1.0 auth required pam_sepermit.so auth substack password-auth auth include postlogin # Used with polkit to reauthorize users in remote sessions -auth optional pam_reauthorize.so prepare account required pam_nologin.so account required pam_access.so account include password-auth password include password-auth # pam_selinux.so close should be the first session rule session required pam_selinux.so close session required pam_loginuid.so # pam_selinux.so open should only be followed by sessions to be executed in the user context session required pam_selinux.so open env_params session required pam_namespace.so ####Trigger with user logout ##### session optional pam_exec.so quiet /var/tmp/post_session.sh #### session optional pam_keyinit.so force revoke session include password-auth session include postlogin # Used with polkit to reauthorize users in remote sessions -session optional pam_reauthorize.so prepare
2. Now you can configure the post trigger script as per you requirement. For the sake of this post I will just append the time of user logout into a file. For example:
# cat /var/tmp/post_session.sh #!/bin/bash if [ "$PAM_TYPE" = "close_session" ]; then date >> /var/tmp/user_logout.out ## This is the action to be performed when user logs out. fi
3. Grant the execute permission to the /var/tmp/post_session.sh script.
# chmod ugo+x /var/tmp/post_session.sh
4. Verify by logging in and out multiple time and you should get the time of all the logouts added to the file /var/tmp/user_logout.out.