Warning on Logon Screen - Ubuntu 16.04 and 14.04

Question

I'm new on Desktop Engineering and i'm working on a project customizing a Ubuntu. I would like to know how to create a Warning before login that looks like the image below for Windows. I've been searching a lot and I didn't find something really helpful.

Thanks in advance.

Example on Windows

That is very broad. Can you give us some more infos: on the gui (gdm,xfce, etc?) or commandline ? everytime a user logs in, or also when they connect ? are these physical machines or maybe there is a remote setup (x2go) ? etc etc — Robert Riedl, Jan 31 '18 at 13:19
I'm using the Unity and lightdm at all. It is for Desktops (non commandline) everytime that a user logs — Carlos Henrique do Amaral, Jan 31 '18 at 14:08
Then notify-send is probably a good fit. See here for more information. — Robert Riedl, Jan 31 '18 at 14:14

score 0 · Answer 1 · answered Jan 31 '18 at 12:27

I use Gnome, so if you do you too then follow this:

You can easily use /etc/issue file to display a pre-login message / login warning banner for text based session. You can also force OpenSSH (SSHD) to display a login message or banner.

GDM customization GDM is a replacement for XDM, the X Display Manager. GDM runs and manages the X servers for both local and remote logins (using XDMCP). You can easily configure GDM to display message. You need to open gdm custom configuration file:

Debian / Ubuntu Linux : Open /etc/gdm/gdm.conf-custom file.

This file is the appropriate place for specifying your customizations to the GDM configuration. If you run gdmsetup, it will automatically edit this file for you and will cause the daemon and any running GDM GUI programs to automatically update with the new configuration. Not all configuration options are supported by gdmsetup, so to modify some values it may be necessary to modify this file directly by hand.

Display a login banner for Gnome / GDM under Linux Open /etc/gdm/custom.conf file:

# vi /etc/gdm/custom.conf

Find out [greeter] section and append following text:

DefaultWelcome=false
Welcome=Message for local users
RemoteWelcome=Message for remote login users

Save and close the file.

Using GUI tool gdmsetup gdmsetup is a graphical tool for easily changing the most commonly used options including greeting messages. As I mentioned earlier gdmsetup does not support changing of all onfiguration variables, so it may be necessary to edit the files by hand for some configurations and security issues. Open X terminal and enter the command:

sudo gdmsetup

Select Local tab > Welcome Messages > Custom > Enter your custom message > Click on Close button to save the changes.

Source: https://www.cyberciti.biz/tips/howto-unix-linux-change-gnome-login-banner.html

I think gdmsetup hasn't been around since 2007. Code for its successor, gdm2setup, hasn't been changed since 2010. In fact the article that you verbally quote is from 2007 and not likely to be useful in 2018. — Jos, Jan 31 '18 at 12:49

Warning on Logon Screen - Ubuntu 16.04 and 14.04

1 Answers1