gerhard

# to generate your dhparam.pem file, run in the terminal
openssl dhparam -out /etc/nginx/ssl/dhparam.pem 2048

gerhard

---
- name: Register New Relic repository.
  get_url: url=http://download.newrelic.com/debian/newrelic.list
           dest=/etc/apt/sources.list.d/newrelic.list

- name: Download repo key.
  apt_key: url=http://download.newrelic.com/548C16BF.gpg

- name: Install New Relic.
  apt: pkg=newrelic-sysmond update_cache=yes

gerhard

class Thing
  def execute
    stubbed_method
  end
end

MyException = Class.new(StandardError)

describe Thing do
  subject(:thing) { Thing.new }

gerhard

if [ $(ls | grep -c "backup.*tgz") > 0 ]
then
  unless folder _purge exists; do
  mkdir _purge
  done

  mv backup*tgz _purge
  mv backup*md5 _purge
fi

gerhard

• Install getmail (aptitude install getmail4)
• Set Up Your Imap Server (tl;dr)
• getmail
• ruby date_based_archive.rb ~/Maildir/.Archive

gerhard

# This is a configuration script for using Rainbows with EventMachine. I'm providing it incase somebody finds it useful. But honestly, you 
# should stop using EventMachine and use threads instead. The ThreadPool version of this is also in my gist list, and I recommend taking a look at that instead.

# NO, SERIOUSLY, STOP USING EVENTMACHINE.

Rainbows! do
  name = 'yourappname'
  use :EventMachine
  client_max_body_size nil # This is set in nginx
  # keepalive_timeout 1

gerhard

Fibur

Fibur is a library that allows concurrency during Ruby I/O operations without needing to make use of callback systems. Traditionally in Ruby, to achieve concurrency during blocking I/O operations, programmers would make use of Fibers and callbacks. Fibur eliminates the need for wrapping your I/O calls with Fibers and a callback. It allows you to write your blocking I/O calls the way you normally would, and still have concurrent execution during those I/O calls.

Example

Say you have a method that fetches data from a network resource:

gerhard

# Here a few bash one-liners that helped me analyze / fight a weak DOS attack against debuggable.com. Mostly for future reference.
# The attacker was opening lots of tcp connections without sending data, I believe it's called a SYN flood, see: http://tools.ietf.org/html/rfc4987#section-3.2

# Step 0: Check what is going on at port 80
$ netstat -tan | grep ':80 ' | awk '{print $6}' | sort | uniq -c

# Step 1: Increase the number of available fds
$ ulimit -n 32000

# Step 2: Restart your webserver, for me:

gerhard

require 'goliath'
require 'em-synchrony/em-http'
 
class TwilioResponse < Goliath::API
  use Goliath::Rack::Params
  use Goliath::Rack::JSONP

  HEADERS = { authorization: ENV.values_at("TWILIO_SID","TWILIO_AUTH_TOKEN") }
  BASE_URL = "https://api.twilio.com/2010-04-01/Accounts/#{ENV['TWILIO_SID']}/AvailablePhoneNumbers/US"

gerhard

require "fiber"
require "rack/fiber_pool"
require "sinatra/base"

require "redis"
require "redis/connection/synchrony"

class App < Sinatra::Base
  use Rack::FiberPool