route53_user_manager.rb

#
# Usage:
#
# export AMAZON_ACCESS_KEY_ID='xxxxxxxxxxxxxxxxxxxx'
# export AMAZON_SECRET_ACCESS_KEY='xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx'
# export BASE_DOMAIN='example.com'
# export RECORD_VALUE='www.example.com'
# 
# ruby route53_user_manager.rb add bouzuya
# #=> bouzuya.example.com. CNAME www.example.com.
# ruby route53_user_manager.rb add aws
# #=> aws.example.com. CNAME www.example.com.
# ruby route53_user_manager.rb list
# #=> bouzuya
# #=> aws
# ruby route53_user_manager.rb remove bouzuya
# ruby route53_user_manager.rb list
# #=> aws

require 'rubygems'
require 'aws-sdk'

BASE_DOMAIN = ENV['ROUTE53_USER_MANAGER_BASE_DOMAIN']
RECORD_VALUE = ENV['ROUTE53_USER_MANAGER_RECORD_VALUE']

class Route53UserManager

  RECORD_TYPE = 'CNAME'
  RECORD_TTL = 300

  def initialize(base_domain, record_value)
    @r53 = AWS::Route53.new
    @hosted_zone = fetch_hosted_zones.select {|zone| zone[:name] == (base_domain + '.') }.first
    @record_value = record_value
    raise if @hosted_zone.nil?
  end

  def add(user)
    validate_user(user)
    name = user + '.' + @hosted_zone[:name]
    type = RECORD_TYPE
    options = { resource_records: [{ value: @record_value }], ttl: RECORD_TTL }
    request = AWS::Route53::CreateRequest.new(name, type, options)
    batch = AWS::Route53::ChangeBatch.new @hosted_zone[:id]
    batch << request
    batch.call
  end

  def remove(user)
    validate_user(user)
    name = user + '.' + @hosted_zone[:name]
    record = fetch_resource_record_sets.select {|r| r[:type] == RECORD_TYPE }.select {|r| r[:name] == name }.first
    return nil if record.nil?
    type = record[:type]
    options = record
    options.delete :name
    options.delete :type
    request = AWS::Route53::DeleteRequest.new(name, type, options)
    batch = AWS::Route53::ChangeBatch.new @hosted_zone[:id]
    batch << request
    batch.call
  end

  def users
    p = Regexp.new(Regexp.quote('.' + @hosted_zone[:name]) + '$')
    fetch_resource_record_sets.select {|r| r[:type] == RECORD_TYPE }.map {|r| r[:name].sub(p, '') }
  end

private

  def fetch_resource_record_sets
    res = @r53.client.list_resource_record_sets hosted_zone_id: @hosted_zone[:id]
    res[:resource_record_sets]
  end

  def fetch_hosted_zones
    res = @r53.client.list_hosted_zones
    res[:hosted_zones]
  end

  def validate_user(user)
    raise if user.nil?
    raise if user.empty?
    raise if user.match(/\./)
  end

end

commands = {}
commands['add'] = lambda do |users|
  manager = Route53UserManager.new BASE_DOMAIN, RECORD_VALUE
  users.each do |user|
    manager.add user
  end
end
commands['remove'] = lambda do |users|
  manager = Route53UserManager.new BASE_DOMAIN, RECORD_VALUE
  users.each do |user|
    manager.remove user
  end
end
commands['list'] = lambda do |_|
  manager = Route53UserManager.new BASE_DOMAIN, RECORD_VALUE
  puts manager.users
end

command = commands[ARGV.shift]
command.call ARGV