For the last month or so I’ve been using the GL Matrix screensaver built into Gnome as my desktop background, and I’m probably not ever going back to a standard background. Other then the fact that it only takes up 10~15 megabytes to run, it doubles as a screensaver. Finding good 1680×1050 backgrounds isn’t an easy task either..

At any rate, if you would like to use the GL Matrix screensaver as your background you must first disable the nautilus desktop:

gconftool-2 --type bool --set /apps/nautilus/preferences/show_desktop false

Now let’s make the desktop entry for our xserver autostart:

gedit ~/.config/autostart/glmatrix.desktop

Just paste the following into your editor and then save it:

[Desktop Entry]
Version=1.0
Encoding=UTF-8
Name=No name
Name[en_IN]=Desktop matrix
Exec=/usr/lib/xscreensaver/glmatrix -root
X-GNOME-Autostart-enabled=true

Once you have done that, restart Gnome by hitting Ctrl+Alt+Backspace.

Going back to the original nautlius desktop is simple:

gconftool-2 --type bool --set /apps/nautlius/preferences/show_desktop true && nautilus

At one time or another, you will most likely want your application to set-up with some preliminary data. One common example is a settings or options table within your database, or a default admin user that will be created upon install.

To get this done, is actually a lot easier then you may think..

Simply create a new migration such as:

script/generate migration add_default_user

Now all you need to do is add the data into the migration.

class AddDefaultUser < ActiveRecord::Migration
  def self.up
      User.create(
        :username => 'default', 
        :password => 'password'
       )
  end
 
  def self.down
  end
end

Once you have your migrations the way you like just run

rake db:migrate

to finish the job.

One thing to consider is deleting any records you have added to this migration in the self.down method, depending on your applications requirements. However, I think that this may also be accomplished when the (user) migration is removed.