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 



196
197
198
199
200
 
# File 'lib/alexandria/book_providers/amazon_ecs_util.rb', line 196

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

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

Yields:

Raises:

  • (ArgumentError) 


57
58
59
60
61
 
# File 'lib/alexandria/book_providers/amazon_ecs_util.rb', line 57

def self.configure(&_proc)
  raise ArgumentError, "Block is required." unless block_given?

  yield @@options
end

.debug ⇒ Object

Get debug flag.



48
49
50
 
# File 'lib/alexandria/book_providers/amazon_ecs_util.rb', line 48

def self.debug
  @@debug
end

.debug=(dbg) ⇒ Object

Set debug flag to true or false.



53
54
55
 
# File 'lib/alexandria/book_providers/amazon_ecs_util.rb', line 53

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

.hmac_sha256(message, key) ⇒ Object 



202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
 
# File 'lib/alexandria/book_providers/amazon_ecs_util.rb', line 202

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 = ""
  (0..key.size - 1).each do |i|
    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.



81
82
83
84
85
86
 
# File 'lib/alexandria/book_providers/amazon_ecs_util.rb', line 81

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].



66
67
68
69
70
71
72
73
74
75
76
77
78
 
# File 'lib/alexandria/book_providers/amazon_ecs_util.rb', line 66

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



34
35
36
 
# File 'lib/alexandria/book_providers/amazon_ecs_util.rb', line 34

def self.options
  @@options
end

.options=(opts) ⇒ Object

Set default search options



43
44
45
 
# File 'lib/alexandria/book_providers/amazon_ecs_util.rb', line 43

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:



176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
 
# File 'lib/alexandria/book_providers/amazon_ecs_util.rb', line 176

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 do |k, v|
    next unless v

    v = v.join(",") if v.is_a? Array
    qs << "&#{camelize(k.to_s)}=#{URI.encode(v.to_s)}"
  end
  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 



38
39
40
 
# File 'lib/alexandria/book_providers/amazon_ecs_util.rb', line 38

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.



96
97
98
99
100
101
102
103
104
105
106
107
 
# File 'lib/alexandria/book_providers/amazon_ecs_util.rb', line 96

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) 


237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
 
# File 'lib/alexandria/book_providers/amazon_ecs_util.rb', line 237

def self.sign_request(request)
  raise AmazonNotConfiguredError unless @@secret_access_key

  # Step 0 : Split apart request string
  url_pattern = %r{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



89
90
91
92
 
# File 'lib/alexandria/book_providers/amazon_ecs_util.rb', line 89

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