Writing static facts is fairly easy even with a low level of Ruby skills. Below is an example of a fact that returns true or false depending on whether the node has a /boot partition:

Facter.add(:has_bootfs) do
  setcode do
    if Facter.value(:mountpoints)['/boot'].nil?
      false
    else
      true
    end
  end
end

As you can see above the required information was already inside the “mountpoints” fact of Facter.

Using the fact is easy: