Kyle Brandt

Introduction
For a system administrator it is important to have an efficient and comfortable interface to all your servers. GNU Screen is an excellent utility to be able to have a single terminal connected to multiple servers that won’t disappear when you close the window. I have a set up that allows me to spawn gnome-terminal with different screen sessions for each location I administer in a different tab. Then each screen session has a named ‘tab’ that automatically logs into each server at that location. It ends up looking like this:

My main two recommendations for screen are to set up the meta character as back-tick ( ` ) and to give screen a ‘tab bar’. You can read how to do these two things here.

Setting up Screen
Once you have screen set up the way you like, you can the specify an additional screenrc file with the -c switch and your settings in the ~/.screenrc will still be used. The secondary screenrc is where you can list different server groups. This file will make it so there are named ‘tabs’ for each server, and each tab will log into the server you specify. Each line in the file should be something like ’screen -t myServer ssh myServer’, the first mySever is the name of the tab, and then ssh myServer is the command that will be run. To simplify doing this in the future, I made a little Perl script that reads a file that has one server name per line and prints the rc file to standard out.

#!/usr/bin/perl
#===============================================================================
#         FILE:  makeScreenRc.pl
#        USAGE:  ./makeScreenRc.pl
#       AUTHOR:  Kyle Brandt (kb), kyle@kbrandt.com
#===============================================================================

use strict;
use warnings;

print "zombie qr\n";
while (<>) {
        chomp;
        my $server = $_;
        print "screen -t $server ssh $server", "\n";
}

So if you called the above script with something like ‘perl makeScreenRc.pl myDmzList > myScreenDmzRc’ you can then use the created file with ’screen -R DMZ -c myScreenDmzRc’. The capital R switch looks for an existing detached session and will attempt to reattach it before creating a new one. This will be useful with gnome-terminal in case gnome-terminal crashes.

Setting Up Gnome-Terminal
The next step is to create a profile for each of the screen sessions. You can do this by going to File::New Profile and then create a profile with a relevant name for the screen session, i.e. ‘DMZ’ . After that, Go to the Title and Command tab, check ‘Run a custom Command instead of my shell’ and and edit the command to be something like ’screen -R DMZ -c myScreenDmzRc’. Then repeat this for each of the screen sessions you have set up. Then, you can run something like ‘gnome-terminal –tab-with-profile=DMZ –tab-with-profile=MyOffice’ where DMZ and MyOffice are the names of the gnome-terminal profiles you created. This automatically detaches itself from the controlling terminal, so if you close the terminal you launched this from, the new terminal will not close. Lastly, you can set up a shell alias to run the above command, so all you have to do to open up your command central is type something like ‘myservers’.