Clean up EC2 snapshots

snapshots.rake

namespace :snapshots do
  desc "cull all snapshots except for 1st of each month and last 60 days."
  task :cull do
    ec2 = Configuration.instance.connection
    snaps = ec2.describe_snapshots
    snaps = snaps.select {|s| DateTime.parse(s[:aws_started_at]) < 60.days.ago }
    snaps.inject({}) { |newhash, h| newhash[Time.parse(h[:aws_started_at])] = h; newhash }
    saved = newhash.keys.group_by { |date| date.month }.map { |k, v| v.first }
    saved.each do |key|
      snaps.delete key
    end
    snaps.each do |snap|
      begin
        ec2.delete_snapshot(snap[:aws_id])
      end
    end
  end