Deacon - human readable random name generator
Out of ideas for incoming bare-metal host names in your cluster? This little gem is a way out! It contains frequently occurring given names and surnames from the 1990 US Census (public domain data):
- 256 (8 bits) unique male given names
- 256 (8 bits) unique female given names
- 65,536 (16 bits) unique surnames
- with over 120 gender-neutral given names
Given names were filtered to be 3-5 characters long, surnames 5-8 characters, therefore generated names are never longer than 14 characters (5+1+8).
This gives 33,554,432 (25 bits) total of male and female name combinations. Built-in generator can either generate randomized succession, or generate combinations based on MAC adresses.
The random name generator makes use of Fibonacci linear feedback shift register which gives deterministic sequence of pseudo-random numbers. Additionally, algorithm makes sure names with same first name (or gender) and last name are not returned in succession. Since there are about 1% of such cases, there are about 33 million unique total names. Example sequence:
- velma-pratico.my.lan
- angie-warmbrod.my.lan
- grant-goodgine.my.lan
- alton-sieber.my.lan
- velma-vanbeek.my.lan
- don-otero.my.lan
- sam-hulan.my.lan
The polynomial used in linear feedback shift register is
x^25 + x^24 + x^23 + x^22 + 1.
The key thing is to store register (a number) and use it for each generation in order to get non-repeating sequence of name combinations. See an example below.
Examples of MAC-based names:
- 24:a4:3c:ec:76:06 -> bobby-louie-sancher-weeler.my.lan
- 24:a4:3c:e3:d3:92 -> bob-louie-sancher-rimando.my.lan
MAC addresses with same OID part (24:a4:3c in this case) generates the same middle name ("Louie Sancher" in the example above), therefore it is possible to guess server (or NIC) vendor from it, or it should be possible to shorten middle names (e.g. bobby-ls-weeler.my.lan) in homogeneous environments.
MAC-based advantages
- reprovisioning the same server generates the same name
- middle names are same for unique hardware vendors
MAC-based disadvantages
- name is longer
Random-based advantages
- name is shorter
Random-based disadvantages
- reprovisioning the same server generates different name
Random LFSR non-repeating generator example:
require "deacon"
register = Deacon::RandomGenerator::random_initial_seed
generator = Deacon::RandomGenerator.new
(1..5).each do |_|
# store the register in non-volatile memory (e.g. on disk)
register, firstname, lastname = generator.generate(register)
puts firstname + ' ' + lastname
end
Example output:
LOREN SPAHN
JULIO GIMBEL
CORY SIBILIO
PATSY CUSSON
HUGH SHIMER
By default, same firstname or surname successions are removed. To avoid that behavior (e.g. in stateless applications where you can't store register), use
register, firstname, lastname = generator.generate(register, false)
Random LFSR generator example:
require "deacon"
generator = Deacon::RandomGenerator.new
(1..5).each do |_|
# ignoring the register can lead to duplicities!
_, firstname, lastname = generator.generate
puts firstname + ' ' + lastname
end
MAC generator example:
require "deacon"
generator = Deacon::MacGenerator.new
firstname, lastname = generator.generate("AA:BB:CC:DD:EE:FF")
puts firstname + ' ' + lastname
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Contains given names and surnames from the 1990 US Census which is PUBLIC DOMAIN. The code is GNU GPL-3.0.
Copyright (c) 2016 Lukas Zapletal
This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/.