gerhard

Instrument Anything in Rails 3

With Rails 3.0 released a few weeks ago I've migrated a few apps and I'm constantly finding useful new improvements. One such improvement is the ability to log anything in the same way that Rails internally logs ActiveRecord and ActionView. By default Rails 3 logs look slightly spiffier than those produced by Rails 2.3: (notice the second line has been cleaned up)

Started GET "/" for 127.0.0.1 at Mon Sep 06 01:07:11 -0400 2010
  Processing by HomeController#index as HTML
  User Load (0.2ms)  SELECT `users`.* FROM `users` WHERE (`users`.`id` = 3) LIMIT 1
  CACHE (0.0ms)  SELECT `users`.* FROM `users` WHERE (`users`.`id` = 3) LIMIT 1

Rendered layouts/_nav.html.erb (363.4ms)

gerhard

Prototype mysql_grant provider for Chef
---------------------------------------

Drop the two files into your mysql cookbook, and experiment with the following examples:

mysql_grant "kenneth" do
  action :grant
  username "root" # <- User with admin privs
  password node[:mysql][:server_root_password]
  # Actual grant details

gerhard

#!/bin/sh
#
# init.d script for single or multiple unicorn installations. Expects at least one .conf 
# file in /etc/unicorn
#
# Modified by jay@gooby.org http://github.com/jaygooby
# based on http://gist.github.com/308216 by http://github.com/mguterl
#
## A sample /etc/unicorn/my_app.conf
## 

gerhard

# Author: Pieter Noordhuis
# Description: Simple demo to showcase Redis PubSub with EventMachine
#
# Requirements:
# - rubygems: eventmachine, thin, cramp, sinatra, yajl-ruby
# - a browser with WebSocket support
#
# Usage:
# ruby redis_pubsub_demo.rb
#

gerhard

gerhard

Coding Rails with Homebrew

Right now, this assumes you are using Snow Leopard.

Install Homebrew

Homebrew is MacPorts (or APT) without the suck. http://github.com/mxcl/homebrew

gerhard

# this goes in ~/.freeagent
ENV['FA_COMPANY']  = 'mycompany'
ENV['FA_USERNAME'] = 'myloginemail'
ENV['FA_PASSWORD'] = 'mypassword'

gerhard

#! /bin/sh

### BEGIN INIT INFO
# Provides:          mongodb
# Required-Start:    $all
# Required-Stop:     $all
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: starts the mongodb data-store
# Description:       starts mongodb using start-stop-daemon

gerhard

require 'money'
require 'xe_exchange'

Money.default_bank = XE::Exchange.instance

ten_dollars = Money.new(1000, 'USD')
ten_dollars_in_pounds = ten_dollars.exchange_to('GBP')

gerhard

 # Taken from passenger_memory_stats script

  # Returns the private dirty RSS for the given process, in KB.
  def determine_private_dirty_rss(pid)
    total = 0
    File.read("/proc/#{pid}/smaps").split("\n").each do |line|
      line =~ /^(Private)_Dirty: +(\d+)/
      if $2
        total += $2.to_i
      end