Class: Fluent::ForestOutput

Inherits:
MultiOutput
  • Object
show all
Defined in:
lib/fluent/plugin/out_forest.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#outputs ⇒ Object (readonly)

Returns the value of attribute outputs.



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# File 'lib/fluent/plugin/out_forest.rb', line 10

def outputs
  @outputs
end

Instance Method Details

#configure(conf) ⇒ Object 



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# File 'lib/fluent/plugin/out_forest.rb', line 17

def configure(conf)
  super

  if @remove_prefix
    @removed_prefix_string = @remove_prefix + '.'
    @removed_length = @removed_prefix_string.length
  end
  if @add_prefix
    @added_prefix_string = @add_prefix + '.'
  end

  @mapping = {} # tag => output
  @outputs = []
  @mutex = Mutex.new

  @template = nil
  @parameter = nil
  @cases = []

  conf.elements.each do |element|
    # read and throw away to supress unread configuration warning
    touch_recursive(element)

    case element.name
    when 'template'
      @template = element
    when 'case', 'pattern'
      matcher = Fluent::GlobMatchPattern.new(element.arg)
      @cases.push([matcher, element])
    end
  end

  self
end

#emit(tag, es, chain) ⇒ Object 



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# File 'lib/fluent/plugin/out_forest.rb', line 154

def emit(tag, es, chain)
  if @remove_prefix and
      ( (tag.start_with?(@removed_prefix_string) and tag.length > @removed_length) or tag == @remove_prefix)
    tag = tag[@removed_length..-1]
  end
  if @add_prefix
    tag = if tag.length > 0
            @added_prefix_string + tag
          else
            @add_prefix
          end
  end

  output = @mapping[tag]
  unless output
    output = plant(tag)
  end
  if output
    if output.respond_to?(:emit_events)
      output.emit_events(tag, es)
    else
      output.emit(tag, es, chain)
    end
    chain.next
  else # cannot plant an output (configuration error, or ...?)
    chain.next
  end
end

#parameter(tag, e, name = 'instance', arg = '') ⇒ Object 



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# File 'lib/fluent/plugin/out_forest.rb', line 68

def parameter(tag, e, name = 'instance', arg = '')
  tag_parts = tag.split('.')
  escaped_tag = tag.gsub('.', @escape_tag_separator)
  pairs = {}
  e.each do |k,v|
    v = v.gsub(/__TAG_PARTS\[-?[0-9]+(?:\.\.\.?-?[0-9]+)?\]__|\$\{tag_parts\[-?[0-9]+(?:\.\.\.?-?[0-9]+)?\]\}/) do |tag_parts_matched|
      matched = /\[(?<first>-?[0-9]+)(?<range_part>(?<range_type>\.\.\.?)(?<last>-?[0-9]+))?\]/.match(tag_parts_matched)
      raise "BUG: gsub regex matches but index regex does not match" unless matched

      if matched[:range_part]
        exclude_end = (matched[:range_type] == '...')
        range = Range.new(matched[:first].to_i, matched[:last].to_i, exclude_end)
        if tag_parts[range]
          tag_parts[range].join(".")
        else
          log.warn "out_forest: missing placeholder. tag:#{tag} placeholder:#{tag_parts_matched} conf:#{k} #{v}"
          nil
        end
      else # non range index (without range_part)
        index = matched[:first].to_i
        unless tag_parts[index]
          log.warn "out_forest: missing placeholder. tag:#{tag} placeholder:#{tag_parts_matched} conf:#{k} #{v}"
        end
        tag_parts[index]
      end
    end
    v = v.gsub('__ESCAPED_TAG__', escaped_tag).gsub('${escaped_tag}', escaped_tag)
    pairs[k] = v.gsub('__TAG__', tag).gsub('${tag}', tag).gsub('__HOSTNAME__', @hostname).gsub('${hostname}', @hostname)
  end
  elements = e.elements.map do |child|
    parameter(tag, child, child.name, child.arg)
  end
  Fluent::Config::Element.new(name, arg, pairs, elements)
end

#plant(tag) ⇒ Object 



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# File 'lib/fluent/plugin/out_forest.rb', line 125

def plant(tag)
  output = nil
  begin
    @mutex.synchronize {
      output = @mapping[tag]
      unless output
        output = Fluent::Plugin.new_output(@subtype)
        output.configure(spec(tag))
        output.start
        output.after_start if output.respond_to?(:after_start)
        @mapping[tag] = output
        @outputs.push(output)
      end
    }
    log.info "out_forest plants new output: #{@subtype} for tag '#{tag}'"
  rescue Fluent::ConfigError => e
    log.error "failed to configure sub output #{@subtype}: #{e.message}"
    log.error e.backtrace.join("\n")
    log.error "Cannot output messages with tag '#{tag}'"
    output = nil
  rescue StandardError, ScriptError => e
    log.error "failed to configure/start sub output #{@subtype}: #{e.message}"
    log.error e.backtrace.join("\n")
    log.error "Cannot output messages with tag '#{tag}'"
    output = nil
  end
  output
end

#shutdown ⇒ Object 



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# File 'lib/fluent/plugin/out_forest.rb', line 61

def shutdown
  super
  @mapping.values.each do |output|
    output.shutdown
  end
end

#spec(tag) ⇒ Object 



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# File 'lib/fluent/plugin/out_forest.rb', line 103

def spec(tag)
  conf = Fluent::Config::Element.new('instance', '', {}, [])
  conf = parameter(tag, @template) + conf if @template # a + b -> b.merge(a) (see: fluentd/lib/fluent/config.rb)
  @cases.each do |m,e|
    if m.match(tag)
      matched_case = parameter(tag, e)

      matched_case.elements.each { |case_child|
        unless case_child.arg.empty?
          conf.elements.delete_if { |conf_child|
            conf_child.name == case_child.name && conf_child.arg == case_child.arg
          }
        end
      }

      conf = matched_case + conf
      break
    end
  end
  conf
end

#touch_recursive(e) ⇒ Object 



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# File 'lib/fluent/plugin/out_forest.rb', line 52

def touch_recursive(e)
  e.keys.each do |k|
    e[k]
  end
  e.elements.each do |child|
    touch_recursive(child)
  end
end