Endpoint authentication

The endpoint authentication use a pair (key, authentication_token).

For key generate is used NumberGenerator module.

module NumberGenerator
  extend ActiveSupport::Concern

  NUMBER_LENGTH  = 9
  NUMBER_LETTERS = false
  NUMBER_PREFIX  = 'N'

  included do
    field :number, type: String
    validates :number, uniqueness: true
    before_validation :generate_number, on: :create
  end
  
  def self.by_number(number)
    where(number: number)
  end
  
  def generate_number(options = {})
    options[:length]  ||= NUMBER_LENGTH
    options[:letters] ||= NUMBER_LETTERS
    options[:prefix]  ||= NUMBER_PREFIX

    possible = (0..9).to_a
    possible += ('A'..'Z').to_a if options[:letters]

    self.number ||= loop do
      # Make a random number.
      random = "#{options[:prefix]}#{(0...options[:length]).map { possible.shuffle.first }.join}"
      # Use the random  number if no other order exists with it.
      if self.number.present? && self.number == random
        # If over half of all possible options are taken add another digit.
        options[:length] += 1 if self.class.count > (10 ** options[:length] / 2)
      else
        break random
      end
    end
  end
 
end

The module decorate Connection class.

module Setup
  class Connection < Base
    include NumberGenerator
    ...
  end
end

Mongoid provide alias functionality, we use alias key for number

  field :number, as: :key, type: String

In the above example you can reference the field by Connection#key, but the field in the database is stored as number.