class AWS::Core::LogFormatter

Log Formatters

Log formatters receive a {AWS::Core::Response} object and return a log message. When you construct a {LogFormatter}, you provide a pattern string with substitutions.

pattern = '[REQUEST :http_status_code] :service :operation :duration'
formatter = AWS::Core::LogFormatter.new(pattern)
formatter.format(response)
#=> '[AWS 200] EC2 get_bucket 0.0352'

AWS Configuration

AWS.config provides a {LogFormatter.default} log formatter. You can repace this formatter by building your own and then passing it to {AWS.config}.

pattern = '[REQUEST :http_status_code] :service :operation :duration'
AWS.config(:log_formatter => AWS::Core::LogFormatter.new(pattern)

Canned Formatters

Instead of providing your own pattern, you can choose a canned log formatter.

AWS.config(:log_formatter => AWS::Core::LogFormatter.colored)

Here is the list of canned formatters.

Pattern Substitutions

You can put any of these placeholders into you pattern.

:service

The AWS service name (e.g. 'S3', 'EC2', 'SimpleDB', etc)

:region

The AWS region name (e.g. 'us-east-1', 'us-west-1', etc)

:operation

The name of the client request method. This maps to the name of the serivce API operation (e.g. :describe_instances).

:options

The hash of options passed to the client request method. Long strings are truncated/summarized if they excede the log formatters {#max_string_size}. Other objects are inspected.

:retry_count

The number of times a client request was retried. Throttlings and service errors trigger the automatic retry logic. This value indicates how many extra attempts were made before getting a successful response or giving up.

:duration

The time it took to generate a response, expressed in decimal seconds. This time includes everything from calling the client request method, until that method returns a value (event retries and retry delays).

:error_class

The class name of the error returned by the service. If no error was returned, this will be replcaed by an empty string.

:error_message

The message of the error returned. If no error was returned by the service, this will be an empty string.

:http_request_method

The HTTP request verb (e.g. 'POST', 'PUT', 'GET', etc).

:http_request_protocol

This is replaced by 'http' or 'https'.

:http_request_host

The host name of the http request endpoint (e.g. 's3.amazon.com').

:http_request_port

The port number (e.g. '443' or '80').

:http_request_uri

The http request uri folling the host (e.g. '/bucket_name/objects/key?versions').

:http_request_body

The http request payload.

:http_request_headers

The http request headers, inspected.

:http_request_proxy_uri

The proxy uri used, or an empty string.

:http_response_status

The http response status code (e.g. '200', '404', '500', etc).

:http_response_headers

The http response headers, inspected.

:http_response_body

The http response body contents.

Attributes

max_string_size[R]

@return [Integer]

pattern[R]

@return [String]

Public Class Methods

new(pattern, options = {}) click to toggle source

@param [String] pattern The log format pattern should be a string

and may contain any of the following placeholders:

* +:service+
* +:region+
* +:operation+
* +:options+
* +:retry_count
* +:duration+
* +:error_class+
* +:error_message+
* +:http_request_method+
* +:http_request_protocol+
* +:http_request_host+
* +:http_request_port+
* +:http_request_uri+
* +:http_request_body+
* +:http_request_headers+
* +:http_request_proxy_uri+
* +:http_response_status+
* +:http_response_headers+
* +:http_response_body+

@param [Hash] options

@option options [Integer] :max_string_size (1000)

# File lib/aws/core/log_formatter.rb, line 157
def initialize pattern, options = {}
  @pattern = pattern
  @max_string_size = options[:max_string_size] || 1000
end

Protected Class Methods

colored() click to toggle source

The default log format with ANSI colors.

@example A sample of the colored format (sans the ansi colors).

[AWS SimpleEmailService 200 0.580066 0 retries] list_verified_email_addresses()

@return [LogFormatter]

# File lib/aws/core/log_formatter.rb, line 438
def colored

  bold = "\x1b[1m"
  color = "\x1b[34m"
  reset = "\x1b[0m"

  pattern = []
  pattern << "#{bold}#{color}[AWS"
  pattern << ":service"
  pattern << ":http_response_status"
  pattern << ":duration"
  pattern << ":retry_count retries]#{reset}#{bold}"
  pattern << ":operation(:options)"
  pattern << ":error_class"
  pattern << ":error_message#{reset}"

  LogFormatter.new(pattern.join(' ') + "\n")

end
debug() click to toggle source

A debug format that dumps most of the http request and response data.

@example A truncated sample of the debug format.

+-------------------------------------------------------------------------------
| AWS us-east-1 SimpleEmailService list_verified_email_addresses 0.429189 0 retries
+-------------------------------------------------------------------------------
|   REQUEST
+-------------------------------------------------------------------------------
|    METHOD: POST
|       URL: https://email.us-east-1.amazonaws.com::443:/
|   HEADERS: {"content-type"=>"application/x-www-form-urlencoded" ...
|      BODY: Action=ListVerifiedEmailAddresses&Timestamp= ...
+-------------------------------------------------------------------------------
|  RESPONSE
+-------------------------------------------------------------------------------
|    STATUS: 200
|   HEADERS: {"x-amzn-requestid"=>["..."], ...
|      BODY: <ListVerifiedEmailAddressesResponse ...

@return [LogFormatter]

# File lib/aws/core/log_formatter.rb, line 389
def debug

  sig_pattern = []
  sig_pattern << ':region'
  sig_pattern << ':service'
  sig_pattern << ':operation'
  sig_pattern << ':duration'
  sig_pattern << ':retry_count retries'

  uri_pattern = []
  uri_pattern << ':http_request_protocol'
  uri_pattern << '://'
  uri_pattern << ':http_request_host'
  uri_pattern << '::'
  uri_pattern << ':http_request_port'
  uri_pattern << ':'
  uri_pattern << ':http_request_uri'

  line = "+" + '-' * 79

  pattern = []
  pattern << line
  pattern << "| AWS #{sig_pattern.join(' ')}"
  pattern << line
  pattern << "|   REQUEST"
  pattern << line
  pattern << "|    METHOD: :http_request_method"
  pattern << "|       URL: #{uri_pattern.join}"
  pattern << "|   HEADERS: :http_request_headers"
  pattern << "|      BODY: :http_request_body"
  pattern << line
  pattern << "|  RESPONSE"
  pattern << line
  pattern << "|    STATUS: :http_response_status"
  pattern << "|   HEADERS: :http_response_headers"
  pattern << "|      BODY: :http_response_body"

  LogFormatter.new(pattern.join("\n") + "\n")

end
default() click to toggle source

The default log format.

@example A sample of the default format.

[AWS SimpleEmailService 200 0.580066 0 retries] list_verified_email_addresses()

@return [LogFormatter]

# File lib/aws/core/log_formatter.rb, line 327
def default

  pattern = []
  pattern << "[AWS"
  pattern << ":service"
  pattern << ":http_response_status"
  pattern << ":duration"
  pattern << ":retry_count retries]"
  pattern << ":operation(:options)"
  pattern << ":error_class"
  pattern << ":error_message"

  LogFormatter.new(pattern.join(' ') + "\n")

end
short() click to toggle source

The short log format. Similar to default, but it does not inspect the request params or report on retries.

@example A sample of the short format

[AWS SimpleEmailService 200 0.494532] list_verified_email_addresses

@return [LogFormatter]

# File lib/aws/core/log_formatter.rb, line 352
def short

  pattern = []
  pattern << "[AWS"
  pattern << ":service"
  pattern << ":http_response_status"
  pattern << ":duration]"
  pattern << ":operation"
  pattern << ":error_class"

  LogFormatter.new(pattern.join(' ') + "\n")

end

Public Instance Methods

==(other)
Alias for: eql?
eql?(other) click to toggle source

@private

# File lib/aws/core/log_formatter.rb, line 175
def eql? other
  other.is_a?(self.class) and other.pattern == self.pattern
end
Also aliased as: ==
format(response) click to toggle source

@param [Response] response @return [String]

# File lib/aws/core/log_formatter.rb, line 170
def format response
  pattern.gsub(/:(\w+)/) {|sym| send("_#{sym[1..-1]}", response) }
end

Protected Instance Methods

_duration(response) click to toggle source
# File lib/aws/core/log_formatter.rb, line 210
def _duration response
  ("%.06f" % response.duration).sub(/0+$/, '')
end
_error_class(response) click to toggle source
# File lib/aws/core/log_formatter.rb, line 214
def _error_class response
  response.error.class.name if response.error
end
_error_message(response) click to toggle source
# File lib/aws/core/log_formatter.rb, line 218
def _error_message response
  response.error.message if response.error
end
_http_request_body(response) click to toggle source
# File lib/aws/core/log_formatter.rb, line 246
def _http_request_body response
  response.http_request.body
end
_http_request_headers(response) click to toggle source
# File lib/aws/core/log_formatter.rb, line 242
def _http_request_headers response
  response.http_request.headers.inspect
end
_http_request_host(response) click to toggle source
# File lib/aws/core/log_formatter.rb, line 230
def _http_request_host response
  response.http_request.host
end
_http_request_method(response) click to toggle source
# File lib/aws/core/log_formatter.rb, line 222
def _http_request_method response
  response.http_request.http_method
end
_http_request_port(response) click to toggle source
# File lib/aws/core/log_formatter.rb, line 234
def _http_request_port response
  response.http_request.port
end
_http_request_protocol(response) click to toggle source
# File lib/aws/core/log_formatter.rb, line 226
def _http_request_protocol response
  response.http_request.use_ssl? ? 'https' : 'http'
end
_http_request_proxy_uri(response) click to toggle source
# File lib/aws/core/log_formatter.rb, line 250
def _http_request_proxy_uri response
  response.http_request.proxy_uri
end
_http_request_uri(response) click to toggle source
# File lib/aws/core/log_formatter.rb, line 238
def _http_request_uri response
  response.http_request.uri
end
_http_response_body(response) click to toggle source
# File lib/aws/core/log_formatter.rb, line 262
def _http_response_body response
  response.http_response.body
end
_http_response_headers(response) click to toggle source
# File lib/aws/core/log_formatter.rb, line 258
def _http_response_headers response
  response.http_response.headers.inspect
end
_http_response_status(response) click to toggle source
# File lib/aws/core/log_formatter.rb, line 254
def _http_response_status response
  response.http_response.status
end
_operation(response) click to toggle source
# File lib/aws/core/log_formatter.rb, line 198
def _operation response
  response.request_type
end
_options(response) click to toggle source
# File lib/aws/core/log_formatter.rb, line 202
def _options response
  summarize_hash(response.request_options) if response.request_options
end
_region(response) click to toggle source
# File lib/aws/core/log_formatter.rb, line 194
def _region response
  response.http_request.region
end
_retry_count(response) click to toggle source
# File lib/aws/core/log_formatter.rb, line 206
def _retry_count response
  response.retry_count
end
_service(response) click to toggle source
# File lib/aws/core/log_formatter.rb, line 190
def _service response
  response.http_request.class.name.split('::')[1]
end
method_missing(method_name, *args) click to toggle source
Calls superclass method
# File lib/aws/core/log_formatter.rb, line 182
def method_missing method_name, *args
  if method_name.to_s.chars.first == '_'
    ":#{method_name.to_s[1..-1]}"
  else
    super
  end
end
summarize_array(array) click to toggle source

@param [Array] array @return [String]

# File lib/aws/core/log_formatter.rb, line 313
def summarize_array array
  "[" + array.map{|v| summarize_value(v) }.join(",") + "]"
end
summarize_file(path) click to toggle source

Given the path to a file on disk, this method returns a summarized inspecton string that includes the file size. @param [String] path @return [String]

# File lib/aws/core/log_formatter.rb, line 307
def summarize_file path
  "#<File:#{path} (#{File.size(path)} bytes)>"
end
summarize_hash(hash) click to toggle source

@param [Hash] hash @return [String]

# File lib/aws/core/log_formatter.rb, line 273
def summarize_hash hash
  hash.map do |key,v|
    "#{key.inspect}=>#{summarize_value(v)}"
  end.sort.join(",")
end
summarize_string(str) click to toggle source

@param [String] str @return [String]

# File lib/aws/core/log_formatter.rb, line 294
def summarize_string str
  max = max_string_size
  if str.size > max
    "#<String #{str[0...max].inspect} ... (#{str.size} bytes)>"
  else
    str.inspect
  end
end
summarize_value(value) click to toggle source

@param [Object] value @return [String]

# File lib/aws/core/log_formatter.rb, line 281
def summarize_value value
  case value
  when String   then summarize_string(value)
  when Hash     then '{' + summarize_hash(value) + '}'
  when Array    then summarize_array(value)
  when File     then summarize_file(value.path)
  when Pathname then summarize_file(value)
  else value.inspect
  end
end