Dump contents of Logstash checkpoint files

checkpoint_scanner.rb

#!/usr/bin/env ruby

class CheckpointDecoder

  attr_reader :path 

  def initialize(path)	
    @path = path	
  end
  
  def decode
    
    puts "filename, version, pageNum, firstUnackedPageNum, firstUnackedSeqNum, minSeqNum, eventCount, checksum"
    if File.file?(path)
      decode_single_file(path)
    else
      Dir.glob(path + '/checkpoint.*').sort.each { |file_name| decode_single_file(file_name) }
    end	
  end	

  private
  def decode_single_file(file_path)
  	file = File.open(file_path)
  	file_name = File.basename(file_path)
  	unpacked = file.read(34).unpack("S>NNLLNN")
    version = unpacked[0]
    pageNum = unpacked[1]
    firstUnackedPageNum = unpacked[2]
    firstUnackedSeqNum = unpacked[3]
    minSeqNum = unpacked[4]
    eventCount = unpacked[5]
    checksum = unpacked[6]
    puts "#{file_name}, #{version}, #{pageNum}, #{firstUnackedPageNum}, #{firstUnackedSeqNum}, #{minSeqNum}, #{eventCount}, #{checksum}"
  end	
end	

if ARGV.length < 1
  puts "Dump content of Logstash queue checkpoint files. CAn work on single file or on a folder full checkpoint files"
  puts "examples: "
  puts "single file: ./checkpoint_scanner.rb data/queue/main/checkpoint.585811 "
  puts "folder: ./checkpoint_scanner.rb data/queue/main "
  exit
end


checkpoint_decoder = CheckpointDecoder.new(ARGV[0])
checkpoint_decoder.decode