 |
| Gratuitous picture of my pets, the day after we rescued them |
Some Background
In March 2014, when I first started looking after MAAS as a product manager, I raised a minor feature request in Bug #1287224, noting that the random, 5-character hostnames that MAAS generates are not ideal. You can't read them or pronounce them or remember them easily. I'm talking about hostnames like: sldna, xwknd, hwrdz or wkrpb. From that perspective, they're not very friendly. Certainly not very Ubuntu.We're not alone, in that respect. Amazon generates forgettable instance names like i-15a4417c, along with most virtual machine and container systems.
So I proposed a few different ways of automatically generating those names, modeled mostly after Ubuntu's beloved own code naming scheme -- Adjective Animal. To get the number of combinations high enough to model any reasonable MAAS user, though, we used Adjective Noun instead of Adjective Animal.
I collected a Adjective list and a Noun list from a blog run by moms, in the interest of having a nice, soft, friendly, non-offensive source of words.
For the most part, the feature served its purpose. We now get memorable, pronounceable names. However, we get a few odd balls in there from time to time. Most are humorous. But some combinations would prove, in fact, to be inappropriate, or perhaps even offensive to some people.
Accepting that, I started thinking about other solutions.
In the mean time, I realized that Docker had recently launched something similar, their NamesGenerator, which pairs an Adjective with a Famous Scientist's Last Name (except they have explicitly blacklisted boring_wozniak, because "Steve Wozniak is not boring", of course!).
Similarly, Github itself now also "suggests" random repo names.
I liked one part of the Docker approach better -- the use of proper names, rather than random nouns.
On the other hand, their approach is hard-coded into the Docker Golang source itself, and not usable or portable elsewhere, easily.
Moreover, there's only a few dozen Adjectives (57) and Names (76), yielding only about 4K combinations (4332) -- which is not nearly enough for MAAS's purposes, where we're shooting for 16M+, with minimal collisions (ie, covering a Class A network).
Introducing the PetName Libraries
MAAS was already pretty good on Adjectives (about 1,300). But I decided to scrap the Nouns list, and instead build a Names list. I started with Last Names (like Docker), but instead focused on First Names, and built a list of about 2,000 names from public census data.The combination actually works pretty well! While smelly-Susan isn't particularly charming, it's certainly not an ad hominem attack targeted at any particular Susan! That 1,300 x 2,000 gives us well over 2 million unique combinations.
Moreover, I also thought about how I could actually make it infinitely extensible... The simple rules of English allow Adjectives to modify Nouns, while Adverbs can recursively modify other Adverbs or Adjectives. How convenient!
So I built a word list of Adverbs (3,600) as well, and added support for specifying the "number" of words in a PetName.
- If you want 1, you get a random Name
- If you want 2, you get a random Adjective followed by a Name
- If you want 3 or more, you get N-2Adverbs, an Adjective and a Name
Note:
- 3 words will generate nearly 10 billion unique combos -- more than a 32-bit unique space (232)
- And 5 words will nearly cover 64-bit space (264).
Shell
So once the algorithm was spec'd out, I built and packaged a simple shell utility and text word lists, called petname, which are published at:- bzr: launchpad.net/petname
- git: github.com/dustinkirkland/petname
- ubuntu: pad.lv/u/petname
$ sudo apt-add-repository ppa:petname/ppa
$ sudo apt-get update
And:
$ sudo apt-get install petname
$ petname
itchy-Marvin
$ petname -w 3
listlessly-easygoing-Radia
$ petname -s ":" -w 5
onwardly:unflinchingly:debonairly:vibrant:Chandler
Python
That's only really useful from the command line, though. In MAAS, we'd want this in a native Python library. So it was really easy to create python-petname, source now published at:The packages are already in Ubuntu 15.04 (Vivid). On any other version of Ubuntu, you can use the PPA:
$ sudo apt-add-repository ppa:python-petname/ppa
$ sudo apt-get update
And:
$ sudo apt-get install python-petname
$ python-petname
flaky-Megan
$ python-petname -w 4
mercifully-grimly-fruitful-Salma
$ python-petname -s "" -w 2
filthyLaurel
Using it in your own Python code looks as simple as this:
$ python
⟫⟫⟫ import petname
⟫⟫⟫ foo = petname.Generate(3, "_")
⟫⟫⟫ print(foo)
boomingly_tangible_Mikayla
Golang
In the way that NamesGenerator is useful to Docker, I though a Golang library might be useful for us in LXD (and perhaps even usable by Docker or others too), so I created:
The packages are already in Ubuntu 15.04 (Vivid). On any other version of Ubuntu, you can use the PPA:
$ sudo apt-add-repository ppa:golang-petname/ppa
$ sudo apt-get update
And:
$ sudo apt-get install golang-petname
$ golang-petname
quarrelsome-Cullen
$ golang-petname -words=1
Vivian
$ golang-petname -separator="|" -words=10
snobbily|oracularly|contemptuously|discordantly|lachrymosely|afterwards|coquettishly|politely|elaborate|Samir
Using it in your own Golang code looks as simple as this:
package main
import (
"fmt"
"math/rand"
"time"
"github.com/dustinkirkland/golang-petname"
)
func main() {
flag.Parse()
rand.Seed(time.Now().UnixNano())
fmt.Println(petname.Generate(2, ""))
}
 |
| Gratuitous picture of my pets, 7 years later. |
happily-hacking-Dustin