EC2 ssh config builder for aliases

ssh_config.rb

#!/usr/bin/env ruby

require 'rubygems'
require 'aws'

File.open("#{ENV['HOME']}/.ssh/config", 'w') do |file|

  @ec2 = Aws::Ec2.new(ENV['AWS_KEY'], ENV['AWS_SECRET'])
  @ec2.describe_instances.each do |instance|
    next unless instance[:aws_state] == 'running'
    file.puts "Host #{instance[:tags]['Name'].sub(/(\d)\D+$/, '\1') }"
    file.puts "  Hostname #{instance[:dns_name]}"
    file.puts "  User ubuntu"
    file.puts
  end

end