ebs-usage.rb

#!/usr/bin/env ruby

require 'aws-sdk'

ec2 = Aws::EC2::Client.new(region: 'us-west-1')

volumes = ec2.describe_volumes.volumes

volume_sizes = {}
volumes.each do |vol|
  volume_sizes[vol.volume_type] ||= []
  volume_sizes[vol.volume_type] << vol.size
end

volume_sizes.each do |type, sizes|
  puts format('%s: %d', type, sizes.reduce(:+))
end