Replay Heroku Logs

replay.rb

require 'time'
require 'thread'
require 'uri'
require 'pry'

filename = ARGV.shift

if !filename
  puts "Specify a filename"
  exit(1)
end

queue = Queue.new

10.times do
  Thread.new do
    loop do
      system queue.pop
    end
  end
end

lines = File.readlines(filename)
last_time = nil
ctr = 0
lines.each do |line|
  if line =~ /(?<=\s)([-\d:T\.\+]+)(?=\sheroku router)/
    time = DateTime.rfc3339($~.to_s).to_time
    last_time ||= time
    req_info = Hash[line.scan(/(?<=\s)(\w+)\=\"?(.+?)[\"|\s]/)]
    if (req_info["dyno"] == "web.3" || req_info["dyno"] == "web.6") && req_info["method"] == "GET"
      ctr += 1
      puts ctr if ctr % 10 == 0
      dt = (time.to_f-last_time.to_f).abs
      uri = URI(ARGV.shift)
      uri.path, _, uri.query = req_info["path"].partition("?")
      uri.query = uri.query.split("&").tap { |q| q << "_token=#{ARGV.shift}" }.join("&")
      fmt_path = req_info["path"].length > 50 ? req_info["path"][0..47] + "..." : req_info["path"]
      puts "Delta-T: %1.2fs \tPath: %50s\tDyno: %5s" % [dt, fmt_path, req_info["dyno"]]
      queue << "curl -s \"#{uri.to_s}\" > /dev/null"
      last_time = time
      sleep dt
    end
  end
end