Chef EC2 Node Cleanup task

chef-ec2.rake

namespace :ec2 do
  # setup chef config
  # assumes this file is sibling to .chef dir, ex: CHEF_REPO/tasks
  config = File.join(File.dirname(__FILE__), '..', '.chef', 'knife.rb')
  Chef::Config.from_file(config)

  require 'active_support'
  require 'aws'

  desc 'Delete any ec2-based chef nodes that no longer exist'
  task :cleanup_nodes do
    aws_access_key = ENV['AMAZON_ACCESS_KEY_ID']
    aws_secret_key = ENV['AMAZON_SECRET_ACCESS_KEY']
    raise "Amazon Environment variables not defined" if aws_access_key.blank? || aws_secret_key.blank?
    ec2 = Aws::Ec2.new(aws_access_key, aws_secret_key)
    # list or running ec2 instance ids
    ec2_instances = ec2.describe_instances.reject{|i| i[:aws_state] == "terminated"}.collect{|i| i[:aws_instance_id]}
    # list of all currently registered chef clients (only ec2 nodes). Assumes instance id is the node name
    chef_ec2_clients = Chef::ApiClient.list.keys.grep(/i-[a-zA-z0-9]+/)
    # list of registered chef clients that aren't currently running.
    dead_chef_ec2_clients = chef_ec2_clients - ec2_instances
    # delete clients
    dead_chef_ec2_clients.each do |dead_client_name|
      dead_client = Chef::ApiClient.load(dead_client_name)
      dead_client.destroy
    end

    chef_ec2_nodes = Chef::Node.list.keys.grep(/i-[a-zA-z0-9]+/)
    dead_ec2_nodes = chef_ec2_nodes - ec2_instances
    # delete nodes
    dead_ec2_nodes.each do |dead_node_name|
      dead_node = Chef::Node.load(dead_node_name)
      dead_node.destroy
    end
  end
end