Automagically launch an EC2 image and then provision it using sunzi

Gemfile

source 'http://rubygems.org'

gem 'sunzi'
gem 'rake'
gem 'fog'

Rakefile

# Create, provision and destroy virtual servers at Amazon EC2
# ===========================================================

begin
  require 'fog'
rescue LoadError
  puts "[!] Please install the 'fog' gem:", "", "  $ gem install fog", ""
  exit(1)
end

STDOUT.sync = true

ACCESS_KEY_ID     = ENV['AWS_ACCESS_KEY_ID']
SECRET_ACCESS_KEY = ENV['AWS_SECRET_ACCESS_KEY']

unless ACCESS_KEY_ID && SECRET_ACCESS_KEY
  puts "[!] Error: Please provide your AWS credentials as environment variables for the script to continue...",
       "export AWS_ACCESS_KEY_ID=<Your AWS access key>",
       "export AWS_SECRET_ACCESS_KEY=<Your AWS secret access key>"
  exit(1)
end

# Create connection to EC2
#
EC2 = Fog::Compute.new provider:              'AWS',
                       region:                'us-east-1',
                       aws_access_key_id:     ACCESS_KEY_ID,
                       aws_secret_access_key: SECRET_ACCESS_KEY


task :default => ['ec2:launch', 'ec2:provision']

namespace :ec2 do

  desc "Launch and provision new micro instance via the Amazon Elastic Computing service"
  task :launch do
    print "Launching new server instance at EC2..."

    # Create new instance...
    s = EC2.servers.bootstrap image_id:   'ami-349b495d',
                              flavor_id:  't1.micro',
                              private_key_path: '~/.ssh/id_rsa', 
                              public_key_path: '~/.ssh/id_rsa.pub',
                              tags:       { Name: 'AppDeployment' },
                              username: 'ubuntu'

    puts "", "Started instance '#{s.id}' (#{s.flavor_id}) at #{s.dns_name}", '-'*80
    puts s.tags
  end

  desc "Terminate all servers tagged 'AppDeployment'"
  task :terminate do
    # Select all instances with the proper tag
    #
    servers = EC2.servers.select { |s| s.tags["Name"] == "AppDeployment" && s.state == "running" }

    if servers.size < 1
      puts "No servers running for testing deployment, exiting...", '-'*80
      exit
    end

    puts "Terminating #{servers.size} running servers...", '-'*80
    servers.each do |s|
      puts "* #{s.id} (#{s.flavor.name})"
      s.destroy
    end
  end

  desc "Provision new server with Sunzi"
  task :provision do
    # Select all instances with the proper tag
    #
    servers = EC2.servers.select { |s| s.tags["Name"] == "AppDeployment" && s.state == "running" }
    
    exec "time bin/sunzi deploy ubuntu@#{servers.first.dns_name}"
  end

  desc "SSH to the new server"
  task :ssh do
    servers = EC2.servers.select { |s| s.tags["Name"] == "AppDeployment" && s.state == "running" }
    puts "Connecting to #{servers.first.dns_name}"
    exec "ssh ubuntu@#{servers.first.dns_name}"
  end
end