Storage Gatewayの監視用スクリプト（CachePercentDirty）

CachePercentDirty.rb

#!/bin/env ruby
# -*- coding: utf-8 -*-

require 'aws-sdk'
require 'time'

ACCESS_KEY = "#{ARGV[0]}"
SECRET_KEY = "#{ARGV[1]}"
gateway_id = "#{ARGV[2]}"
gateway_name = "#{ARGV[3]}"
REGION = "#{ARGV[4]}"

start_time = Time.now - 10800
end_time = Time.now

## AWSへの認証を行います
cw = AWS::CloudWatch.new(
  :access_key_id => ACCESS_KEY,
  :secret_access_key => SECRET_KEY,
  :cloud_watch_endpoint => REGION
).client

## メトリクスのオプションを指定して値を取得します
statistics = cw.get_metric_statistics({
  :namespace   => 'AWS/StorageGateway',
  :metric_name => 'CachePercentDirty',
  :statistics  => ['Average'],
  :dimensions  => [
  { :name => "GatewayId", :value => gateway_id },
  { :name => "GatewayName", :value => gateway_name }
  ],
  :period      => 300,
  :start_time  => start_time.iso8601,
  :end_time    => end_time.iso8601,
})

## 値を出力します
p statistics[:datapoints][0][:average]