Generating GUIDs in Ruby
RubyGuidRuby Problem Overview
I have a problem that is really easily solved with GUIDs.
In particular, for a password reset workflow, I would like to send a GUID token to a user's email and have them reset their password using the token. Since GUIDs are unique, this is pretty secure and saves me emailing people passwords, which is risky.
I noticed there is one uuid gem @ rubyforge but it looks quite old, and it writes stuff to the file system.
Does anyone know of any other gems that can create a globally unique identifier?
I know I can just fall back to:
(0..16).to_a.map{ |a| rand(16).to_s(16) }.join
But it does not really seem like a proper GUID ...
Ruby Solutions
Solution 1 - Ruby
As of Ruby 1.9, uuid generation is built-in. Use the SecureRandom.uuid function.
For example:
require 'securerandom'
SecureRandom.uuid # => "96b0a57c-d9ae-453f-b56f-3b154eb10cda"
Solution 2 - Ruby
How to create small, unique tokens in Ruby
>> require 'digest'
=> []
>> Digest::SHA1.hexdigest("some-random-string")[8..16]
=> "2ebe5597f"
>> SecureRandom.base64(8).gsub("/","_").gsub(/=+$/,"")
=> "AEWQyovNFo0"
>> rand(36**8).to_s(36)
=> "uur0cj2h"
Solution 3 - Ruby
Did you look at UUIDTools?
> UUIDTools was designed to be a simple library for generating any of the various types of UUIDs (or GUIDs if you prefer to call them that). It conforms to RFC 4122 whenever possible.
Solution 4 - Ruby
Google yields the following Ruby library:
http://raa.ruby-lang.org/project/ruby-guid/
Also, over at http://www.ruby-forum.com/topic/99262 they say you can install a gem (execute gem uuid on the command line to install it) and then do
gem 'uuid'
puts UUID.new
in your code to see a new UUID.
(Hint: I Googled for guid ruby)
Solution 5 - Ruby
To create a proper, mysql, varchar 32 GUID
SecureRandom.uuid.gsub('-','').upcase
Solution 6 - Ruby
Small update to Simone Carletti answer:
> SecureRandom.base64(8).gsub("/","_").gsub(/=+$/,"")
> => "AEWQyovNFo0"
can be replaced with:
>SecureRandom.urlsafe_base64(8)
Solution 7 - Ruby
While programming late at night I came up with the following solution (based off Simone's) for generating a unique GUID in Rails. I am not proud of it but it does work quite well.
while Order.find_by_guid(guid = rand(36**8).to_s(36).upcase).present?; end
Solution 8 - Ruby
This is a neet technique I learnt from JavaScript:
def uuid
"xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx".gsub("x") do
"0123456789ABCDEF"[rand(16)]
end
end
Although in a more 'ruby way' one could also do:
def uuid
"xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx".gsub("x") do
rand(16).to_s(16)
end
end
Solution 9 - Ruby
> When I used uuid gems recommended in this question, no one can generate unique and random UUID. My answer is a work around, if we have gem later to satisfy the request, you'd better to use gem in Ruby.
I try most recommended uuid gems in this question, but no one make me satisfied, we need unique and random uuid. I directly run system command uuidgen in ruby, and I like the result, and share here.
puts `uuidgen`
8adea17d-b918-43e0-b82f-f81b3029f688
puts `uuidgen`
6a4adcce-8f64-41eb-bd7e-e65ee6d11231
puts `uuidgen`
51d5348b-8fc3-4c44-a6f7-9a8588d7f08a
puts `uuidgen`
332a0fa3-7b07-41e1-9fc8-ef804a377e4e
if compare with uuid gem, you will know the difference.
irb(main):003:0> uuid.generate
=> "40cdf890-ebf5-0132-2250-20c9d088be77"
irb(main):004:0> uuid.generate
=> "4161ac40-ebf5-0132-2250-20c9d088be77"
Test environment is linux and Mac OS environment.
Solution 10 - Ruby
For rails running a postgreSQL database do 2 things.
Step 1: generate a scaffold/model
rails g scaffold manager name:string --primary-key-type=uuid
Step 2: Add a line to migration file
If you rails db:migrate now, you'll get a PG::UndefinedFunction: ERROR: function gen_random_uuid() does not exist error.
So add this to the migration file
enable_extension 'pgcrypto' unless extension_enabled?('pgcrypto')
Example:
class CreateManagers < ActiveRecord::Migration[7.0]
enable_extension 'pgcrypto' unless extension_enabled?('pgcrypto')
def change
create_table :managers, id: :uuid do |t|
t.string :name
t.timestamps
end
end
end
You're done!
Oh one last thing, you only nee to add enable_extension 'pgcrypto' unless extension_enabled?('pgcrypto') to one migration file (e.g. the first time you use uuid type).