IronSavior

#!/bin/env ruby

# Create CNAME records in Route 53 that refer to the running EC2 instance
# Unless specified by the first argument, a default TTL of 300 is assumed.
# Instance tags specify CNAMES to be set:
#  'set_cname:0' => 'name.example.com', 'set_cname:1' => 'name2.example.com', etc

# Uses IAM credentials found in the AWS CLI config file:
#  ~/.aws/config (use `aws configure` to create)
# Depends on ec2-metadata command to retrieve the current instance ID

IronSavior

#!/bin/env ruby

### The Poor-Man's DNS Zone Transfer
# Copy specific records from a specific name service to Route 53, without using a conventional zone transfer mechanism.
#
# I realize this is unorthodox and might seem less-than-optimal for most use-cases.  In my case, this is a means to
# help me continue to utilize Dreamhost's "Fully Hosted Domain" features even after migrating the authority of my zones
# as well as my name service to Route 53.  The correct functioning of my web hosting and my email services depend on
# the ability of dreamhost to freely manage a known subset of the records in my zone.  I chose to solve this by
# periodically copying that set of records from Dreamhost's name server for my domain into its actual authoritative

IronSavior

# Author:  Erik Elmore <erik@erikelmore.com>
# License:  Public Domain

# A lazy-loaded collection with built-in lookup indexing.
# Good for using lots of memory.
class IndexedCollection
  include Enumerable
  
  DEFAULT_DATA = Array[].freeze
  DEFAULT_LOADER = ->(){ DEFAULT_DATA }.freeze

IronSavior

# Author:  Erik Elmore <erik@erikelmore.com>
# License:  Public Domain

# Enable "diffing" and two-way transformations between collection objects
module Diffable
  # Calculates the changes required to transform self to the given collection.
  # @param b [Enumerable] The other collection object
  # @return [Array] The Diff: A two-element change set representing items to exclude and items to include
  def diff( b )
    a, b = to_a, b.to_a

IronSavior

# Author:  Erik Elmore <erik@erikelmore.com>
# License:  Public Domain
require 'securerandom'
require 'aws'

# Test the feasability of using temporary queues and topics as a means of receiving
# notifications from remote systems via SQS and SNS. TestClient creates either only a
# queue or both a queue and a topic before sending a request to the server. When the
# client wishes to receive its response directly in a temporary queue, the request
# body is the URL to its temporary queue. When the client wishes to be notified via a

IronSavior

# Author:  Erik Elmore <erik@erikelmore.com>
# License:  Public Domain

# Convenience in logging
module LogMethods
  def error( *args, &blk )
    log :error, *args, &blk
  end
  private :error
  

IronSavior

module NormalizeHeredoc
  module_function
  # Normalize indents, like for heredoc strings
  def NormalizeIndent( msg )
    msg = String(msg)
    depth = msg.scan(/^\s*/).flatten.map(&:size).min
    msg.gsub(/^\s{#{depth}}/, '')
  end
end

IronSavior

# Enforces upper bound on the frequency of arbitrary actions.
# Thread-safe, but not terribly efficient.
class RateLimit
  # Blocks passed to #enforce are executed with a frequency not exceeding the average of +limit+ calls per +period+ over
  # +burst+ consecutive periods. Thread safe, but be advised there are no guarantees about the order or timeliness in
  # which the given blocks are executed.
  # @param limit [Numeric] Target average number of events per period
  # @param period [Numeric] Duration of period in seconds (or equivalent, like ActiveSupport::Duration)
  # @param burst [Numeric] Number of periods over which to average
  def initialize( limit, period = 1, burst = 3 )

IronSavior

# Fixed point combinator. Because reasons.
# @param [Block with arity 1] Receives recursion Proc, must return Proc representing function (any arity)
# @return [Proc] 
def Y
  fail unless block_given?
  lambda{ |fn| fn.call fn }.call lambda{ |fn|
    lambda{ |*args|
      (yield fn.call fn).call *args
    }
  }

IronSavior

class HashlikeFetchCache
  include HashlikeOverlay

  def initialize( context )
    @overlay = Hash[]
    @context = context
    freeze
  end

  def []( key )