Custom fact for figuring out which Ganglia grid a given host goes in

grid.rb

#!/usr/bin/ruby
# grid.rb

def find_grid(hostname)
  grid = "admin"
  if hostname =~ (/^(build|launch|util)\d{1,4}/)
    grid = $1
  elsif hostname =~ (/^www\d{1,4}/)
    grid = "web"
  end

  return grid
end

if __FILE__ == $0
  if ARGV[0]
    print find_grid(ARGV[0]), "\n"
  end
else
  begin
    Facter.hostname
  rescue
    Facter.loadfacts()
  end
  hostname = Facter.value("hostname")
  grid = find_grid(hostname)
  Facter.add("grid") do
    setcode do
      grid
    end
  end
end