Class: AwsPricing::PriceList

Inherits:
Object
  • Object
show all
Defined in:
lib/amazon-pricing/aws-price-list.rb

Overview

PriceList provides the primary interface for retrieving AWS pricing. Upon instantiating a PriceList object, all the corresponding pricing information will be retrieved from Amazon via currently undocumented json APIs.

Constant Summary collapse

RETRY_LIMIT = 
3

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ PriceList

Returns a new instance of PriceList.



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# File 'lib/amazon-pricing/aws-price-list.rb', line 20

def initialize()
  @_regions = {}

  # Creating regions upfront since different json files all use different naming conventions. No more ad-hoc creation.
  regions = ["eu-west-1", "sa-east-1", "us-east-1", "ap-northeast-1", "us-west-2", "us-west-1", "ap-southeast-1", "ap-southeast-2",
		 "eu-central-1", "us-gov-west-1", "us-gov-east-1", "ap-northeast-2", "ap-south-1", "us-east-2", "ca-central-1", "eu-west-2", "eu-west-3",
 "ap-northeast-3", "eu-north-1", "ap-east-1"]

  regions.each do |name|
    @_regions[name] = Region.new(name)
  end
end

Instance Attribute Details

#regions ⇒ Object

Returns the value of attribute regions.



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# File 'lib/amazon-pricing/aws-price-list.rb', line 17

def regions
  @regions
end

Class Method Details

.fetch_url(url) ⇒ Object 



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# File 'lib/amazon-pricing/aws-price-list.rb', line 60

def self.fetch_url(url)
  # AWS appears to have started throttling URL accesses, so we now have to retry
  begin
    retry_count ||= 0
    #$stdout.puts "[#{__method__}] url:#{url}"
    uri = URI.parse(url)
    page = Net::HTTP.get_response(uri)
  rescue StandardError => e  #Exception => e
    $stderr.puts "Exception:#{e} retry-#{retry_count} Failed to fetch: #{url}"
    sleep 5 # appears to get past (AWS) throttling
    retry if (retry_count += 1) <= RETRY_LIMIT
  end

  # Now that AWS switched from json to jsonp, remove first/last lines
  body = page.body.gsub("callback(", "").reverse.sub(")", "").reverse
  if body.split("\n").last == ";"
    # Now remove one more line (rds is returning ";", ec2 empty line)
    body = body.reverse.sub(";", "").reverse
  elsif body[-1] == ";"
    body.chop!
  end

  begin
    JSON.parse(body)
  rescue JSON::ParserError
    # Handle "json" with keys that are not quoted
    # When we get {foo: "1"} instead of {"foo": "1"}
    # http://stackoverflow.com/questions/2060356/parsing-json-without-quoted-keys
    JSON.parse(body.gsub(/(\w+)\s*:/, '"\1":'))
  end
rescue Exception => e
  $stderr.puts "Exception:#{e} Failed to parse: #{url} #{e.backtrace}"
  raise e
end

Instance Method Details

#get_instance_type(region_name, api_name) ⇒ Object 



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# File 'lib/amazon-pricing/aws-price-list.rb', line 54

def get_instance_type(region_name, api_name)
  region = get_region(region_name)
  raise "Region #{region_name} not found" if region.nil?
  region.get_instance_type(api_name)
end

#get_instance_types ⇒ Object 



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# File 'lib/amazon-pricing/aws-price-list.rb', line 44

def get_instance_types
  instance_types = []
  @_regions.each do |region|
    region.ec2_instance_types.each do |instance_type|
      instance_types << instance_type
    end
  end
  instance_types
end

#get_region(name) ⇒ Object

EBS now reports regions correctly but all else still has the old format - so we need to handle both region mapping and non-mapping



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# File 'lib/amazon-pricing/aws-price-list.rb', line 35

def get_region(name)
  #@_regions[@@Region_Lookup[name] || name]
  @_regions[convert_region(name)]
end