aws_ebs_raid6 lwrp

ebs_raid6_provider.rb

include Chef::Mixin::Command

action :create do
  size = new_resource.size
  volumes = new_resource.volumes.times.map{|i| (i == 0 ? "/dev/sdf" : "/dev/sdf#{i}") }
  setra = new_resource.blockdev_setra
  volume_group = new_resource.volume_group
  logical_volume = new_resource.name
  mdadm_device = new_resource.mdadm_device
  mount_point = new_resource.mount_point

  log "aws_ebs_raid6: setting up #{volumes.count}x #{size}G EBS volumes"
  log "aws_ebs_raid6: VG: #{volume_group} LV: #{logical_volume} MP: #{mount_point}"

  aws = data_bag_item("aws", node.app_environment)
  volumes.map do |vol|
    aws_ebs_volume "aws_ebs_raid6: #{vol} #{size}" do
      aws_access_key aws['aws_access_key_id']
      aws_secret_access_key aws['aws_secret_access_key']
      size size
      device vol
      action [ :create, :attach ]
    end
  end

  package "mdadm"

  kernel_module "raid456"

  mdadm mdadm_device do
    devices volumes
    level 6
    chunk new_resource.chunk
    action [ :create, :assemble]
  end

  execute "LVM: Initialize physical disk '#{mdadm_device}'" do
    command "pvcreate #{mdadm_device}"
    not_if "pvdisplay #{mdadm_device}"
  end

  execute "LVM: Create volume group #{volume_group}" do
    command "vgcreate #{volume_group} #{mdadm_device}"
    not_if "vgdisplay #{volume_group}"
  end

  execute "LVM: Create #{logical_volume}" do
    command "lvcreate -n #{logical_volume} -l 100%FREE #{volume_group}"
    not_if "lvdisplay /dev/mapper/#{volume_group}-#{logical_volume}"
  end

  execute "XFS: Format /dev/mapper/#{volume_group}-#{logical_volume}" do
    action :nothing
    subscribes :run, resources(:execute => "LVM: Create #{logical_volume}"), :immediately
    command "mkfs.xfs -d su=64k,sw=#{volumes.count - 2}" +
      " /dev/mapper/#{volume_group}-#{logical_volume}"
  end

  execute "LVM: Expand #{logical_volume}" do
    command "lvextend -l 100%FREE /dev/mapper/#{volume_group}-#{logical_volume}"
    only_if do
      status,
      stdout,
      stderr = output_of_command "lvs --nosuffix --noheadings -o size --units m " +
        "/dev/mapper/#{volume_group}-#{logical_volume}", {} #lameo

      raid6_efficiency = (1 - (2 / volumes.count.to_f))
      total_size = (size * volumes.count.to_f)
      available_storage = stdout.strip.to_f

      Chef::Log.debug "aws_ebs_raid6: expand check: " +
        "#{available_storage} < #{total_size} * #{raid6_efficiency}: " +
        "#{available_storage < total_size * raid6_efficiency}"

      available_storage < total_size * raid6_efficiency
    end
  end

  execute "XFS: Grow FS /dev/mapper/#{volume_group}-#{logical_volume}" do
    action :nothing
    subscribes :run, resources(:execute => "LVM: Expand #{logical_volume}"), :immediately
    command "xfs_growfs /dev/mapper/#{volume_group}-#{logical_volume}"
  end

  directory mount_point do
    recursive true
  end

  execute "blockdev --setra #{setra} /dev/mapper/#{volume_group}-#{logical_volume}" do
    not_if "blockdev --getra /dev/mapper/#{volume_group}-#{logical_volume} | grep #{setra}"
  end

  mount mount_point do
    device "/dev/mapper/#{volume_group}-#{logical_volume}"
    fstype "xfs"
    options "rw,noatime,inode64,nobarrier"
    action [ :mount, :enable ]
  end

  log "aws_ebs_raid6: mount #{mount_point} now available"
end

ebs_raid6_resource.rb

actions :create, :snapshot
attribute :size, :kind_of => Integer, :default => 100
attribute :volumes, :kind_of => Integer, :default => 7
attribute :chunk, :kind_of => Integer, :default => 64
attribute :blockdev_setra, :kind_of => Integer, :default => 65536
attribute :volume_group, :kind_of => String, :default => "ebs_raid6"
attribute :mdadm_device, :kind_of => String, :default => "/dev/md0"
attribute :mount_point, :kind_of => String, :default => "/mnt/raid6"