class Fluent::RecordTransformerFilter

Public Instance Methods

configure(conf) click to toggle source
Calls superclass method Fluent::Filter#configure
# File lib/fluent/plugin/filter_record_transformer.rb, line 43
def configure(conf)
  super

  map = {}
  # <record></record> directive
  conf.elements.select { |element| element.name == 'record' }.each do |element|
    element.each_pair do |k, v|
      element.has_key?(k) # to suppress unread configuration warning
      map[k] = parse_value(v)
    end
  end

  if @keep_keys
    raise Fluent::ConfigError, "`renew_record` must be true to use `keep_keys`" unless @renew_record
  end

  placeholder_expander_params = {
    log: log,
    auto_typecast: @auto_typecast,
  }
  @placeholder_expander =
    if @enable_ruby
      # require utilities which would be used in ruby placeholders
      require 'pathname'
      require 'uri'
      require 'cgi'
      RubyPlaceholderExpander.new(placeholder_expander_params)
    else
      PlaceholderExpander.new(placeholder_expander_params)
    end
  @map = @placeholder_expander.preprocess_map(map)

  @hostname = Socket.gethostname
end
filter_stream(tag, es) click to toggle source
# File lib/fluent/plugin/filter_record_transformer.rb, line 78
def filter_stream(tag, es)
  new_es = MultiEventStream.new
  tag_parts = tag.split('.')
  tag_prefix = tag_prefix(tag_parts)
  tag_suffix = tag_suffix(tag_parts)
  placeholder_values = {
    'tag'        => tag,
    'tag_parts'  => tag_parts,
    'tag_prefix' => tag_prefix,
    'tag_suffix' => tag_suffix,
    'hostname'   => @hostname,
  }
  last_record = nil
  es.each do |time, record|
    last_record = record # for debug log
    placeholder_values['time'] = @placeholder_expander.time_value(time)
    placeholder_values['record'] = record
    new_record = reform(record, placeholder_values)
    if @renew_time_key && new_record.has_key?(@renew_time_key)
      time = new_record[@renew_time_key].to_i
    end
    @remove_keys.each { |k| new_record.delete(k) } if @remove_keys
    new_es.add(time, new_record)
  end
  new_es
rescue => e
  log.warn "failed to reform records", error_class: e.class, error: e.message
  log.warn_backtrace
  log.debug "map:#{@map} record:#{last_record} placeholder_values:#{placeholder_values}"
end

Private Instance Methods

expand_placeholders(value, placeholders) click to toggle source
# File lib/fluent/plugin/filter_record_transformer.rb, line 134
def expand_placeholders(value, placeholders)
  if value.is_a?(String)
    new_value = @placeholder_expander.expand(value, placeholders)
  elsif value.is_a?(Hash)
    new_value = {}
    value.each_pair do |k, v|
      new_key = @placeholder_expander.expand(k, placeholders, true)
      new_value[new_key] = expand_placeholders(v, placeholders)
    end
  elsif value.is_a?(Array)
    new_value = []
    value.each_with_index do |v, i|
      new_value[i] = expand_placeholders(v, placeholders)
    end
  else
    new_value = value
  end
  new_value
end
parse_value(value_str) click to toggle source
# File lib/fluent/plugin/filter_record_transformer.rb, line 111
def parse_value(value_str)
  if value_str.start_with?('{', '[')
    JSON.parse(value_str)
  else
    value_str
  end
rescue => e
  log.warn "failed to parse #{value_str} as json. Assuming #{value_str} is a string", error_class: e.class, error: e.message
  value_str # emit as string
end
reform(record, placeholder_values) click to toggle source
# File lib/fluent/plugin/filter_record_transformer.rb, line 122
def reform(record, placeholder_values)
  placeholders = @placeholder_expander.prepare_placeholders(placeholder_values)

  new_record = @renew_record ? {} : record.dup
  @keep_keys.each do |k|
    new_record[k] = record[k] if record.has_key?(k)
  end if @keep_keys && @renew_record
  new_record.merge!(expand_placeholders(@map, placeholders))

  new_record
end
tag_prefix(tag_parts) click to toggle source
# File lib/fluent/plugin/filter_record_transformer.rb, line 154
def tag_prefix(tag_parts)
  return [] if tag_parts.empty?
  tag_prefix = [tag_parts.first]
  1.upto(tag_parts.size-1).each do |i|
    tag_prefix[i] = "#{tag_prefix[i-1]}.#{tag_parts[i]}"
  end
  tag_prefix
end
tag_suffix(tag_parts) click to toggle source
# File lib/fluent/plugin/filter_record_transformer.rb, line 163
def tag_suffix(tag_parts)
  return [] if tag_parts.empty?
  rev_tag_parts = tag_parts.reverse
  rev_tag_suffix = [rev_tag_parts.first]
  1.upto(tag_parts.size-1).each do |i|
    rev_tag_suffix[i] = "#{rev_tag_parts[i]}.#{rev_tag_suffix[i-1]}"
  end
  rev_tag_suffix.reverse!
end