Power button to suspend a Ubuntu desktop edit

I want to suspend the machine when I press the power button. I'm using Linux Mint and it's based on Ubuntu so it's same.

Install dconf-tools: sudo apt-get install dconf-tools Press alt+f2 and open dconf-editor (or in a terminal type dconf-editor) Navigate to org.gnome.settings-daemon.plugins.power and set your default button-power action there:

Even though the option is already set for your desired option, click the option and mark as modified(blod).

or

This is the quick, simple answer I needed:

# gsettings set org.gnome.settings-daemon.plugins.power button-power 'hibernate'

If you want to see your settings first, try this:

# gsettings list-recursively org.gnome.settings-daemon.plugins.power

After edit dconf options, restart the machine.