Ruby script to parse a rails log file and gist the error and source files.

tattletail.rb

require "cgi"
require "net/http"
require "uri"

def error(msg, code = -1)
  puts(msg)
  exit(code)
end

def add_gist_file(gist, number, name, content, ext = File.extname(name))
  gist << "&" << CGI::escape("file_name[gistfile#{number}]")     << "=" << CGI::escape(name)
  gist << "&" << CGI::escape("file_contents[gistfile#{number}]") << "=" << CGI::escape(content)
  gist << "&" << CGI::escape("file_ext[gistfile#{number}]")      << "=" << CGI::escape(ext)
end

in_rails_app = File.exists?("script/rails") || File.exists?("script/server")

if in_rails_app
  print("Rails environment to look at [development]: ")
  environment = gets.strip
  environment = "development" if environment.empty?

  file = "log/#{environment}.log"
  error("No log for environment `#{environment}' exists") unless File.exists?(file)
else
  print("Rails log file to look at: ")
  file = gets.strip

  error("No log found at `#{file}'") unless File.exists?(file)
end

error_regexp = /^(\w+(::\w*)* \((.|[\n])*?\):(\n    .*)*(\n  .*)*)\n$/
log = File.read(file)

errors = log.scan(error_regexp)
error("No errors detected in `#{file}', are you sure it's the right file?") if errors.empty?

error_index = errors.count - 1
selected_error = nil
loop do
  selected_error = errors[error_index][0]

  puts("\nError (#{error_index + 1} of #{errors.count}):")
  puts(selected_error.gsub(/^/, "  "))
  puts

  can_go_back    = error_index > 0
  can_go_forward = error_index < errors.count - 1

  actions = ["y|yes", "#1-#{errors.count}"]
  actions << "p|prev" if can_go_back
  actions << "n|next" if can_go_forward

  print("Submit this error (#{actions.join(' ')}) [yes]: ")
  action = gets.strip

  case action
    when /\A(y|yes)\Z/i, ""
      break
    when /\A-?\d+\Z/
      index = action.to_i - 1
      if (0...errors.count).include?(index) then error_index = index; else puts("Number is out of range") end
    when /\A(p|prev)\Z/i
      if can_go_back then error_index -= 1; else puts("Cannot go to previous error") end
    when /\A(n|next)\Z/i
      if can_go_forward then error_index += 1; else puts("Cannot go to next error") end
    else
      puts("Unknown action: #{action}")
  end
end

if in_rails_app
  print("\nInclude source of files in stack trace [yes]: ")
  include_source = !(gets.strip =~ /\A(n|no)\Z/i)
end

gist, gist_files = "action_button=private", 1
add_gist_file(gist, gist_files, "_log", selected_error, ".txt") && gist_files += 1

if include_source
  puts("\nIncluding source files:")

  source_file_regexp = /^  (.*):\d+(:(.*))?$/
  source_files = selected_error.scan(source_file_regexp)

  puts("  none detected") if source_files.empty?
  source_files.map { |f| f[0] }.uniq.each do |source_file|
    begin
      add_gist_file(gist, gist_files, source_file, File.read(source_file)) && gist_files += 1
      puts("  + `#{source_file}'")
    rescue
      puts("  - `#{source_file}': unable to read file")
    end
  end
end

provider = Net::HTTP
begin
  http = provider.new("gist.github.com", 443)
  http.use_ssl = true

  result = http.post("/gists.xml", gist)

  url = result['Location']

  if url == "https://gist.github.com/gists/new"
    error("\nError creating gist")
  else
    puts("\nYour error gist is available at #{url}")
    exit(0)
  end
rescue SocketError
  puts
  print("Unable to connect to gist.github.com. Use a HTTP proxy [no]: ")
  use_proxy = !!(gets.strip =~ /\A(y|yes)\Z/i)

  if use_proxy
    print("  Proxy host: ")
    host = gets.strip
    print("  Proxy port: ")
    port = gets.strip.to_i
    provider = Net::HTTP::Proxy(host, port)
    retry
  else
    error("Cannot submit gist")
  end
end