shivaram

On master node

wget http://archive.cloudera.com/cdh5/one-click-install/redhat/6/x86_64/cloudera-cdh-5-0.x86_64.rpm
sudo yum --nogpgcheck localinstall cloudera-cdh-5-0.x86_64.rpm
sudo yum clean all
sudo yum install hadoop-hdfs-namenode
sudo yum install R git
sudo yum install spark-core spark-master spark-python

cd

dhh

# config/routes.rb
resources :documents do
  scope module: 'documents' do
    resources :versions do
      post :restore, on: :member
    end

    resource :lock
  end
end

hopsoft

# lib/tasks/db.rake
namespace :db do

  desc "Dumps the database to db/APP_NAME.dump"
  task :dump => :environment do
    cmd = nil
    with_config do |app, host, db, user|
      cmd = "pg_dump --host #{host} --username #{user} --verbose --clean --no-owner --no-acl --format=c #{db} > #{Rails.root}/db/#{app}.dump"
    end
    puts cmd

rwz

# config/initializers/lol_json.rb

module ActiveSupport
  module JSON
    module Encoding
      class JSONGemEncoder
        BYPASS_JSONIFY = Set.new
        
        alias_method :original_jsonify, :jsonify
        

profh

# decode_session_cookie.rb
# ------------------------
# The purpose of this script is to show that if I have the secret_key_base
# and a cookie to an active Rails session, I can decrypt it and gain access
# to key information about the user's session.

require 'rubygems'
require 'cgi'
require 'active_support'

sstephenson

class X.Example extends X.Object
  @proxyMethod "attachmentManager.manageAttachment"
  # Equivalent to:
  #   manageAttachment: -> 
  #     @attachmentManager.manageAttachment.apply(@attachmentManager, arguments)

  @proxyMethod "delegate?.compositionDidChangeDocument"
  # Equivalent to:
  #   compositionDidChangeDocument: ->
  #     @delegate?.compositionDidChangeDocument?.apply(@delegate, arguments)

timcowlishaw

#!/usr/bin/env bash
DATABASE_NAME=your_db_name
BACKUP_PATH=/home/you/backups/db
BACKUP_LIMIT=4
pg_dump $DATABASE_NAME | gzip -c > "$BACKUP_PATH"/"$DATABASE_NAME"_`date +"%Y%m%d%H%M"`.sql.gz
BC=$(ls $BACKUP_PATH | wc -l)
if [ "$BC" -ge "$BACKUP_LIMIT" ]; then
  ls -t $BACKUP_PATH | tail -$(($BC-$BACKUP_LIMIT)) | xargs -I{} rm $BACKUP_PATH/{}
fi

tenderlove

#!/usr/bin/env ruby --disable-gems

# Tab completion for minitest tests.
#
# INSTALLATION:
#
# 1. Put this file in a directory in your $PATH.  Make sure it's executable
# 2. Run this:
#
#   $ complete -o bashdefault -f -C /path/to/this/file.rb ruby

tristanm

Migrating a Rails project from MySQL to PostgreSQL

This brief guide is written from my own experience with migrating a large (~5GB) MySQL database to PostgreSQL for a Rails project.

No warranties, guarantees, support etc. Use at your own risk and, as always, ENSURE YOU MAKE BACKUPS FIRST!

I chose [pgloader][1] because it's extremely fast. YMMV.

1. Replace mysql2 gem with pg in Gemfile.
2. Update config/database.yml for PostgreSQL. I used [Rails' template][2] as a starting point.

pixeltrix

When should you use DateTime and when should you use Time?

It's a common misconception that [William Shakespeare][1] and [Miguel de Cervantes][2] died on the same day in history - so much so that UNESCO named April 23 as [World Book Day because of this fact][3]. However because England hadn't yet adopted [Gregorian Calendar Reform][4] (and wouldn't until [1752][5]) their deaths are actually 10 days apart. Since Ruby's Time class implements a [proleptic Gregorian calendar][6] and has no concept of calendar reform then there's no way to express this. This is where DateTime steps in:

>> shakespeare = DateTime.iso8601('1616-04-23', Date::ENGLAND)
=> Tue, 23 Apr 1616 00:00:00 +0000
>> cervantes = DateTime.iso8601('1616-04-23', Date::ITALY)
=> Sat, 23 Apr 1616 00:00:00 +0000