watched-log

.gitignore

.error-notifier.rb.swp

agent.rb

require './watched_log.rb'

run([
    ['rpm_test_app/log/newrelic_agent.log', RUBY_ERRORS],
    ['rpm_site/java_collector/log/collector.8081.log', JAVA_ERRORS],
    ['rpm_site/beacon/log/server.9000.log', JAVA_ERRORS],])

Gemfile

source 'https://rubygems.org'

gem 'terminal-notifier'
gem 'file-tail'

Gemfile.lock

GEM
  remote: https://rubygems.org/
  specs:
    file-tail (1.0.12)
      tins (~> 0.5)
    terminal-notifier (1.4.2)
    tins (0.6.0)

PLATFORMS
  ruby

DEPENDENCIES
  file-tail
  terminal-notifier

watched_log.rb

require 'terminal-notifier'
require 'file-tail'

$newrelic_root = ARGV[0] || Dir.pwd

RUBY_ERRORS = [
  /(ERROR \: .*)/,
]

JAVA_ERRORS = [
  /( FATAL .*)/,
  /(.*Exception\:.*)/,
  /(.*Exception$)/,
]

def tail_file(path, patterns)
  Thread.new do 
    full_path = File.absolute_path(File.join($newrelic_root, path))
    File.open(full_path) do |log|
      log.extend(File::Tail)
      log.interval = 10
      log.backward(10)

      log.tail do |line|
        match = patterns.map { |r| r.match(line) }.compact.first
        if !match.nil?
          TerminalNotifier.notify(normalize_error(match[0]),
                                  :title => path,
                                  :open => "file://#{full_path}") 
        end
      end
    end
  end
end

def normalize_error(original)
  original.gsub(/[\[\]\(\)]/, '_')
end

def run(logs_to_watch)
  threads = []

  logs_to_watch.each do |log_pair|
    threads << tail_file(log_pair[0], log_pair[1])
  end

  threads.each { |t| t.join }
end