Script to manage ebs raid volumes with logical names and timestamps

manage_ebs_raid.rb

require 'rubygems'
require 'fog'
require 'ap'
require 'time'

def print_usage()
  puts "Assumes all devices from sdc to sdz are available"
  puts "Usage: volume attach [aws instance id] ['raid-name' tag value] ['snap-time' tag value]"
  puts "Usage: volume detach ['raid-name' tag value] ['snap-time' tag value]"
  puts "Usage: volume create ['raid-name' tag value] ['snap-time' tag value]"
  puts "Usage: snapshot create ['raid-name' tag value]  [previous 'snap-time' tag value (optional)] [new raid tag (optional)]"
  exit 1
end

settings = YAML.load_file("#{ENV['HOME']}/.fog")
aws_access_key = settings['default']['aws_access_key_id']
aws_secret_key = settings['default']['aws_secret_access_key']

AWS = Fog::Compute.new(:provider => 'AWS', :aws_access_key_id => aws_access_key, :aws_secret_access_key => aws_secret_key)

def attach_volume(instance_id, raid_tag, snap_time)
  ec2instance = AWS.servers.get(instance_id)
  puts("Attaching volumes to: #{ec2instance.tags['Name']}")

  volumes = get_vols_by_tags(raid_tag, snap_time)
  devices = ('sdc'..'sdz').to_a
  volumes.each_with_index do |vol, i|
    puts("Attaching #{vol.id} => /dev/#{devices[i]}")
    vol.device = "/dev/#{devices[i]}"
    vol.server = ec2instance
  end
end

def detach_volume(raid_tag, snap_time)
  volumes = get_vols_by_tags(raid_tag, snap_time)
  volumes.each do |vol|
    puts("Detaching #{vol.id}...")
    vol.device = nil
    vol.server = nil
  end
end

def create_volume(raid_tag, snap_time)
  snapshots = AWS.snapshots.all({'tag:raid-name'=> raid_tag, 'tag:snap-time' => snap_time})
  new_snap_time =  Time.now.to_i;
  puts("Creating raid-name #{raid_tag} with snap-time #{new_snap_time}")
  snapshots.each do |snap|
    puts("Creating volume from snapshot id #{snap.id}")
    volume = AWS.volumes.new :snapshot_id => snap.id, :size => snap.volume_size, :availability_zone => 'us-east-1c'
    volume.save
    add_tags(volume, raid_tag, new_snap_time)
  end
end

def create_snapshot(raid_tag, prev_snap_time, new_raid_tag)
  if(new_raid_tag == nil)
    new_raid_tag = raid_tag
  snap_time =  Time.now.to_i;
  puts("Creating snapshot collection with raid-name tag #{new_raid_tag} and snap-time of #{snap_time}")

  volumes = get_vols_by_tags(raid_tag, prev_snap_time)
  volumes.each_with_index do |vol, i|
    puts("Snapshotting volume #{vol.id} with raid-name #{new_raid_tag} and snap-time #{snap_time}...")
    snap = AWS.snapshots.new :volume_id => vol.id, :description => "Snapshot of raid-name #{new_raid_tag} from #{Time.now}"
    snap.save
    add_tags(snap, new_raid_tag, snap_time)
  end
end

def get_vols_by_tags(raid_tag, snap_time)
  if(snap_time == nil)
    return AWS.volumes.all({'tag:raid-name'=> raid_tag})
  else
    return AWS.volumes.all({'tag:raid-name'=> raid_tag, 'tag:snap-time' => snap_time})
  end
end

def add_tags(resource, raid_tag, snap_time)
  snap_tag = AWS.tags.new :resource_id => resource.id, :key => 'snap-time', :value => snap_time
  snap_tag.save
  raid_tag_obj = AWS.tags.new :resource_id => resource.id, :key => 'raid-name', :value => raid_tag
  raid_tag_obj.save
end

if ARGV.length >= 3
  category = ARGV.shift
  action = ARGV.shift
  if category == 'volume'
    if action == 'attach'
      if ARGV.length == 3
        attach_volume(ARGV.shift, ARGV.shift, ARGV.shift)
        exit 0
      end
    elsif action == 'detach'
      if ARGV.length == 2
        detach_volume(ARGV.shift, ARGV.shift)
        exit 0
      end
    elsif action == 'create'
      if ARGV.length == 2
        create_volume(ARGV.shift, ARGV.shift)
        exit 0
      end
    end
  elsif category == 'snapshot'
    if action == 'create'
      create_snapshot(ARGV.shift, ARGV.shift, ARGV.shift)
      exit 0
    end
  end
end
print_usage