Class: Amazon::Ecs

Inherits:
Object
  • Object
show all
Includes:
Alexandria::Logging
Defined in:
lib/alexandria/book_providers/amazon_ecs_util.rb

Defined Under Namespace

Classes: Response

Constant Summary collapse

SERVICE_URLS = 
{ us: 'http://webservices.amazon.com/onca/xml?Service=AWSECommerceService',
uk: 'http://webservices.amazon.co.uk/onca/xml?Service=AWSECommerceService',
ca: 'http://webservices.amazon.ca/onca/xml?Service=AWSECommerceService',
de: 'http://webservices.amazon.de/onca/xml?Service=AWSECommerceService',
jp: 'http://webservices.amazon.co.jp/onca/xml?Service=AWSECommerceService',
fr: 'http://webservices.amazon.fr/onca/xml?Service=AWSECommerceService' }.freeze
@@options = 
{}
@@debug = 
false
@@secret_access_key = 
''

Class Method Summary collapse

Methods included from Alexandria::Logging

included, #log

Class Method Details

.camelize(s) ⇒ Object 



215
216
217
218
219
 
# File 'lib/alexandria/book_providers/amazon_ecs_util.rb', line 215

def self.camelize(s)
  s.to_s.
    gsub(/\/(.?)/) { '::' + Regexp.last_match[1].upcase }.
    gsub(/(^|_)(.)/) { Regexp.last_match[2].upcase }
end

.configure {|@@options| ... } ⇒ Object

Yields:

Raises:

  • (ArgumentError) 


81
82
83
84
 
# File 'lib/alexandria/book_providers/amazon_ecs_util.rb', line 81

def self.configure(&_proc)
  raise ArgumentError, 'Block is required.' unless block_given?
  yield @@options
end

.debug ⇒ Object

Get debug flag.



72
73
74
 
# File 'lib/alexandria/book_providers/amazon_ecs_util.rb', line 72

def self.debug
  @@debug
end

.debug=(dbg) ⇒ Object

Set debug flag to true or false.



77
78
79
 
# File 'lib/alexandria/book_providers/amazon_ecs_util.rb', line 77

def self.debug=(dbg)
  @@debug = dbg
end

.hmac_sha256(message, key) ⇒ Object 



221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
 
# File 'lib/alexandria/book_providers/amazon_ecs_util.rb', line 221

def self.hmac_sha256(message, key)
  block_size = 64
  ipad = "\x36" * block_size
  opad = "\x5c" * block_size
  if key.size > block_size
    d = Digest::SHA256.new
    key = d.digest(key)
  end

  ipad_bytes = ipad.bytes.map { |b| b }
  opad_bytes = opad.bytes.map { |b| b }
  key_bytes = key.bytes.map { |b| b }
  ipad_xor = ''
  opad_xor = ''
  for i in 0..key.size - 1
    ipad_xor << (ipad_bytes[i] ^ key_bytes[i])
    opad_xor << (opad_bytes[i] ^ key_bytes[i])
  end

  ipad = ipad_xor + ipad[key.size..-1]
  opad = opad_xor + opad[key.size..-1]

  # inner hash
  d1 = Digest::SHA256.new
  d1.update(ipad)
  d1.update(message)
  msg_hash = d1.digest

  # outer hash
  d2 = Digest::SHA256.new
  d2.update(opad)
  d2.update(msg_hash)
  d2.digest
end

.item_lookup(item_id, opts = {}) ⇒ Object

Search an item by ASIN no.



103
104
105
106
107
108
 
# File 'lib/alexandria/book_providers/amazon_ecs_util.rb', line 103

def self.item_lookup(item_id, opts = {})
  opts[:operation] = 'ItemLookup'
  opts[:item_id] = item_id

  send_request(opts)
end

.item_search(terms, opts = {}) ⇒ Object

Search amazon items with search terms. Default search index option is ‘Books’. For other search type other than keywords, please specify :type => [search type param name].



88
89
90
91
92
93
94
95
96
97
98
99
100
 
# File 'lib/alexandria/book_providers/amazon_ecs_util.rb', line 88

def self.item_search(terms, opts = {})
  opts[:operation] = 'ItemSearch'
  opts[:search_index] = opts[:search_index] || 'Books'

  type = opts.delete(:type)
  if type
    opts[type.to_sym] = terms
  else
    opts[:keywords] = terms
  end

  send_request(opts)
end

.options ⇒ Object

Default search options



58
59
60
 
# File 'lib/alexandria/book_providers/amazon_ecs_util.rb', line 58

def self.options
  @@options
end

.options=(opts) ⇒ Object

Set default search options



67
68
69
 
# File 'lib/alexandria/book_providers/amazon_ecs_util.rb', line 67

def self.options=(opts)
  @@options = opts
end

.prepare_url(opts) ⇒ Object

protected

def self.log(s)
  return unless self.debug
  if defined? RAILS_DEFAULT_LOGGER
    RAILS_DEFAULT_LOGGER.error(s)
  elsif defined? LOGGER
    LOGGER.error(s)
  else
    puts s
  end
end

Raises:



196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
 
# File 'lib/alexandria/book_providers/amazon_ecs_util.rb', line 196

def self.prepare_url(opts)
  country = opts.delete(:country)
  country = country.nil? ? 'us' : country
  request_url = SERVICE_URLS[country.to_sym]
  raise Amazon::RequestError, "Invalid country '#{country}'" unless request_url

  qs = ''
  opts.each { |k, v|
    next unless v
    v = v.join(',') if v.is_a? Array
    qs << "&#{camelize(k.to_s)}=#{URI.encode(v.to_s)}"
  }
  url = "#{request_url}#{qs}"
  # puts ">>> base url >> #{url}"
  signed_url = sign_request(url)
  # puts ">>> SIGNED >> #{signed_url}"
  signed_url
end

.secret_access_key=(key) ⇒ Object 



62
63
64
 
# File 'lib/alexandria/book_providers/amazon_ecs_util.rb', line 62

def self.secret_access_key=(key)
  @@secret_access_key = key
end

.send_request(opts) ⇒ Object

Generic send request to ECS REST service. You have to specify the :operation parameter.



117
118
119
120
121
122
123
124
125
126
127
 
# File 'lib/alexandria/book_providers/amazon_ecs_util.rb', line 117

def self.send_request(opts)
  opts = options.merge(opts) if options
  request_url = prepare_url(opts)
  log.debug { "Request URL: #{request_url}" }

  res = transport.get_response(URI.parse(request_url))
  unless res.is_a? Net::HTTPSuccess
    raise Amazon::RequestError, "HTTP Response: #{res.code} #{res.message}"
  end
  Response.new(res.body)
end

.sign_request(request) ⇒ Object

Raises:

  • (AmazonNotConfiguredError) 


256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
 
# File 'lib/alexandria/book_providers/amazon_ecs_util.rb', line 256

def self.sign_request(request)
  raise AmazonNotConfiguredError unless @@secret_access_key
  # Step 0 : Split apart request string
  url_pattern = /http:\/\/([^\/]+)(\/[^\?]+)\?(.*$)/
  url_pattern =~ request
  host = Regexp.last_match[1]
  path = Regexp.last_match[2]
  param_string = Regexp.last_match[3]

  # Step 1: enter the timestamp
  t = Time.now.getutc # MUST be in UTC
  stamp = t.strftime('%Y-%m-%dT%H:%M:%SZ')
  param_string += "&Timestamp=#{stamp}"

  # Step 2 : URL-encode
  param_string = param_string.gsub(',', '%2C').gsub(':', '%3A')
  #   NOTE : take care not to double-encode

  # Step 3 : Split the parameter/value pairs
  params = param_string.split('&')

  # Step 4 : Sort params
  params.sort!

  # Step 5 : Rejoin the param string
  canonical_param_string = params.join('&')

  # Steps 6 & 7: Prepend HTTP request info
  string_to_sign = "GET\n#{host}\n#{path}\n#{canonical_param_string}"

  # puts string_to_sign

  # Step 8 : Calculate RFC 2104-compliant HMAC with SHA256 hash algorithm
  sig = hmac_sha256(string_to_sign, @@secret_access_key)
  base64_sig = [sig].pack('m').strip

  # Step 9 : URL-encode + and = in sig
  base64_sig = CGI.escape(base64_sig)

  # Step 10 : Add the URL encoded signature to your request
  "http://#{host}#{path}?#{param_string}&Signature=#{base64_sig}"
end

.transport ⇒ Object

HACK : copied from book_providers.rb



111
112
113
114
 
# File 'lib/alexandria/book_providers/amazon_ecs_util.rb', line 111

def self.transport
  config = Alexandria::Preferences.instance.http_proxy_config
  config ? Net::HTTP.Proxy(*config) : Net::HTTP
end