Macworld 2008 - IT854 - Riding the Rails on OS X

8/14/2019 Macworld 2008 - IT854 - Riding the Rails on OS X

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Riding the Rails on OS X Leopard

IT854

Brian Pittspolibyte.com

1/18/2008
http://find/http://goback/


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IntroductionRubyRails

DeploymentAdministration

Conclusion

Outline

1 Introduction2 Ruby

OverviewRakeRubyGems

3 RailsHistory

PhilosophyAnatomy

4 DeploymentOverview

MongrelApacheMisc

5 AdministrationCapistrano

MaintenanceScaling

6 Conclusion

Brian Pitts polibyte.com Riding the Rails on OS X Leopard


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Conclusion


Ruby History

An object-oriented, interpreted programming language

First release by Yukihiro Matsumoto in 1995

Inspired by Perl and Smalltalk



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Conclusion


Ruby in Leopard

Latest stable release: ruby 1.8.6

In framework form:/System/Library/Frameworks/Ruby.framework/

Interpreter and library are universal binaries

Library is 64-bit too


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Conclusion


Rake Overview

Alternative to the make program

Rakefiles are written in pure Ruby

Used to automate many housekeepings tasks in Rails


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Conclusion


Rake Example

/Users/brian/Rakefile

namespace :macworld do

desc "This task will submit a session proposal"

task :submit_proposal doputs "Submitted Proposal"

end

desc "This task will give the talk"

task :give_talk => :submit_proposal doputs "Gave Talk"

end

end


Introduction


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Conclusion


Rake Example

Output

$ rake macworld:give_talk

(in /Users/brian)

Submitted Proposal

Gave Talk


Introduction


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Conclusion


RubyGems Overview

Rubys packaging system

RubyForge is Rubys equivalent to Perls CPAN

Organized with one gem per directory


Introduction


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Conclusion


RubyGems Examples

List installed gems: gem query local

Search gems: gem search remote FOO

Install the latest version of a gem: gem install remoteinclude-dependencies FOO

Install a specific gem version: add version BAR to above

Update an installed gem: gem update FOO

Show details of a gem: gem specification FOOUninstall a gem: gem uninstall FOO

Uninstall old gems: gem clean


Introduction


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Conclusion


RubyGems on Leopard

RubyGems 0.9.4 is installedPre-installed Gems are under/System/Library/Frameworks/Ruby.framework/

Gems you install are in /Library/Ruby/Gems/1.8


Introduction


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RubyRails


Conclusion


Building Gems

Most gems are pure Ruby, but some involve C

Have the Xcode Developer Tools installed

By default Leopard builds universal gems

You can specify the architecture with ARCHFLAGS=-archi386 or -arch ppc


Introduction


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RubyRails


Conclusion

HistoryPhilosophyAnatomy

Rails History

Extracted by David Heinemeier Hansson from his work on

BasecampFirst public release in July 2004

Agile Web Development with Rails published in September2005

Version 2.0 released December 17 2007


Introduction


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RubyRails


Conclusion


Rails Users

A few sites on Rails include

Penny Arcade

CNETs Chow

YellowPages.com

and of course, Twitter


Introduction


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RubyRails


Conclusion


Rails Philosophy

Model-View-Controller (MVC)Convention over Configuration (CoC)

Dont Repeat Yourself (DRY)


IntroductionR b


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RubyRails


Conclusion


Anatomy of Rails

Active Record

Active Resource

Action Pack

Active Support

Action Mailer


IntroductionR b


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RubyRails


Conclusion


Anatomy of a Rails App

Standard directory structureThree environments

DevelopmentTestProduction


IntroductionRuby


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RubyRails


Conclusion


app/

Contains subdirectories with the code for

Controllers

Helpers

Models

Views


IntroductionRuby


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RubyRails


Conclusion


config/

Important configuration parameters

database.yml

environment.rb

environment/


IntroductionRuby

Hi


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RubyRails


Conclusion


config/database.yml

Database connection parameters for the three environments

Sampleproduction:

adapter: mysql

database: chunky_production

username: chunky

host: db.bacon.com


IntroductionRuby

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RubyRails


Conclusion


Database Adapters

Available database adapters

DB2

Firebird

Frontbase

MySQL

Openbase

Oracle

Postgres

SQLite

SQL Server

Sybase

Configuration for each variesBrian Pitts polibyte.com Riding the Rails on OS X Leopard

IntroductionRuby

Histor


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yRails


Conclusion


Installing MySQL

Download and install package from mysql.comRun MySQLStartupItem.pkg

Set environment to ppc or i386

gem install mysql with-mysql-dir=/usr/local/mysql


IntroductionRuby

History


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RailsDeployment

AdministrationConclusion


Creating Databases

Create databases

CREATE DATABASE chunky development;CREATE DATABASE chunky test;CREATE DATABASE chunky production;

Assign permissions


IntroductionRuby

History


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RailsDeployment



config/environment.rb

Application-wide settings, such as

Version of Rails

Session Store

Log level

Sample

RAILS_GEM_VERSION = 1.2.6

config.log_level = :debug# create the session table with rake db:sessions:create

config.action_controller.session_store = :active_record_st


IntroductionRubyR il

History


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RailsDeployment



Sessions

PStore - default, flat files of serialized dataactive record store - database

drb store - DRb server

mem cache store - memcached


IntroductionRubyR il

History


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RailsDeployment


yPhilosophyAnatomy

environments/

3 files, one for each environment

Specify options only for that environmentSample

environments/production.rb

config.action controller.consider all request local = false



History


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RailsDeployment


yPhilosophyAnatomy

db/

Autogenerated schema.rb

Migrations



History


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RailsDeployment


PhilosophyAnatomy

Migrations

Programatically define changes to databaseRun with rake db:migrateApplied in order

001 create users.rb

class AddUsers < ActiveRecord::Migration

def self.up

create_table :users do |t|

t.column :name, :string

t.column :age, :integerend

end

def self.down

drop_table :users

end Brian Pitts polibyte.com Riding the Rails on OS X Leopard


History


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RailsDeployment


PhilosophyAnatomy

doc/

Application documentation in HTML

Generated with rake doc:app



HistoryPhil h


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RailsDeployment


PhilosophyAnatomy

lib/

Code that isnt in MVCOften used for shared code

tasks/ for application-specific rake tasks



HistoryPhil h


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Conclusion

PhilosophyAnatomy

log/

Log file for each environmentLogs contain exception reports, database queries, profilinginformation, and more

Log level can be debug, info, error, or fatal



HistoryPhilosophy


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Conclusion

PhilosophyAnatomy

public/

Document root for Apache



HistoryPhilosophy


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Conclusion

PhilosophyAnatomy

script/

Miscellaneous scripts such as

breakpointer

console

runner

process/ - used to control FastCGI

performance/ - benchmarker and profiler



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HistoryPhilosophy


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Conclusion

PhilosophyAnatomy

test/

Programs and supporting files for

Unit

Functional

Integration

tests.

Run the tests with rake test

First time create the test database with rake db:test:prepare



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HistoryPhilosophy


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Conclusion

PhilosophyAnatomy

tmp/

Temporary files



Deplo ment

HistoryPhilosophy


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Conclusion

p yAnatomy

vendor/

plugins/

Rails

rake rails:freeze:gemsrake rails:freeze:edgerake rails:unfreeze



Deployment

OverviewMongrelApache


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Conclusion

ApacheMisc

Deployment Overview

Considered more complicated than writing a simple Rails app

No working mod ruby for Railscgi = unusably slow

First common approach was FastCGI, but this was unreliable

Current favorite is cluster of mongrel web servers behind a

load balancer



Deployment



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Conclusion

ApacheMisc

Mongrel Overview

Created by Zed Shaw

HTTP server written in 2500 lines of C and RubyIntended for use as a Rails application server

Start one up with mongrel rails start -e production -d -p3000

Connect at http://bacon.com:3000



Deployment



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Conclusion

ApacheMisc

Mongrel Clustering

1 Mongrel = 1 Request

A cluster of mongrels = Many requests

mongrel rails cluster::configure -p 3000 -e production -a127.0.0.1 -N 3 -c /var/chunky/current/

Produces config/mongrel cluster.yml which can be furthertweaked

Start cluster with mongrel rails cluster::startMongrels are on 3000, 3001, and 3002



Deployment



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ep oy e tAdministration

Conclusion

pac eMisc

Launchd for Mongrel Cluster

Credit to Jake Schutz

Program

/opt/local/bin/daemondo

ProgramArguments

--label=mongrel_cluster

--start-cmd

/usr/local/bin/mongrel_rails

cluster::start-C

(Path to your Mongrel Cluster config.yml)


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p yAdministration

Conclusion

pMisc

Launchd for Mongrel Cluster

--stop-cmd

/usr/local/bin/mongrel_rails

cluster::stop

-C

(Path to your Mongrel Cluster config.yml)


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Misc

How Many Mongrels?

Average request time * peak request10 per CPU core

Leave some free RAM



Deployment



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Misc

Apache Overview

Swiss army knife of web servers

Included in OS X

mod proxy balancer

Fast at serving static content



DeploymentAd i i i

OverviewMongrelApacheMi


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Misc

Proxy Balancer Definition

BalancerMember http://127.0.0.1.3000





DeploymentAd i i t ti

OverviewMongrelApacheMi


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Misc

Proxy Configuration

ServerName www.bacon.com

RequestHeader set X_FORWARDED_HOST www.bacon.com

DocumentRoot /var/chunky/current/public

Options FollowSymLinks

AllowOverride None

Order allow,deny

Allow from all




OverviewMongrelApacheMisc


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Misc

Proxy Configuration

RewriteEngine On

# Check for static index and cached pages.

RewriteRule ^/$ /index.html [QSA]RewriteRule ^([^.]+)$ $1.html [QSA]

# No static file exists, let Mongrel handle the request

RewriteCond %{DOCUMENT_ROOT}/%{REQUEST_FILENAME} !-f

RewriteRule ^/(.*)$ balancer://chunky%{REQUEST_URI} [P,QSA




OverviewMongrelApacheMisc


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Misc

Apps outside of document root

Set mongrels prefix option

If app at http://bacon.com/chunky, prefix is chunky/Add appropriate rewrite rule

RewriteRule ^/chunky(.*)$ balancer://chunky%{REQUEST_URI}

This allows multiple apps under the same domain




CapistranoMaintenanceScaling


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Capistrano Overview

Deployment tool written in Ruby

Allows you to deploy or rollback releases with one commandEach deployment goes into releases/, current/ is symlink tolatest deployment

Retrieves application from SCM, default is subversion

Communicates with servers using ssh






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Capistrano Setup

If config/deploy.rb doesnt exist, run capify /Users/fox/chunkychunky

require mongrel_cluster/recipes

set :application, "chunky"

set :repository, "http://svn.bacon.com/#{application}"

set :scm_username, fox

set :scm_password, proc{Capistrano::CLI.password_prompt(S

set :deploy_to, "/var/#{application}"

set :mongrel_conf, "#{current_path}/config/mongrel_clusterrole :web, "bacon.com"

role :app, "bacon.com"

role :db, "bacon.com" , :primary => true






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Conclusion

Running Capistrano

Make sure you can connect to your SCM from your servers

Make sure the user apache and mongrel run as can ready files

created by the user who runs capThe first time, cap deploy:setup

cap deploy

cap deploy:migrations

cap deploy:rollback






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Conclusion

Capistrano Callbacks

You can write cap tasks yourself. E.G. perform more tasks after adeployment

deploy.rb

task :symlink_database_yml do

run "ln -sf #{shared_path}/config/database.yml

#{release_path}/config/database.yml"

end

after deploy:update_code, symlink_database_yml

deploy.rb






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Conclusion

Email Notifications

You can get email notifications of application errors by

Configuring Active Mailer

Installing the exception notification plugin

Modifying the ApplicationController Class




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Conclusion

Configuring Active Mailer

In config/environment.rb

Example

config.action_mailer.delivery_method = :smtpconfig.action_mailer.server_settings = {

:address => "mail.bacon.com",

:port => 25,

:domain => "bacon.com",

}




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Conclusion

Configuring exception notification

ruby script/plugin install exception notification

Add include ExceptionNotifiable toapp/controllers/application.rb

Add ExceptionNotifier.exception.recipients =[[email protected], [email protected]] toconfig/environment.rb




Conclusion



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Conclusion

Housekeeping

Script and automate

Log rollover

Clearing sessions

DB Example

RAILS_ENV=PRODUCTION ./script/runner \

ActiveRecord::Base.connection.delete(

"DELETE FROM sessions WHERE updated_at < now() - 3600")




Conclusion



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Conclusion

Multiple Apps, One Host

Seperate

mongrel cluster

proxy balancer://

rewrite rule

virtualhost (if multiple domains)

for each app.


Introduction

RubyRails


Conclusion



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Conclusion

One App, Multiple Hosts

Optimize the app

Dedicated database server, more mongrels on your application

serverThe path from here varies

Multiple application servers and dedicated front-end loadbalancer

Beefy database server or replication


Introduction

RubyRails


Conclusion



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Conclusion

Trends to watch

Patches to mongrel (evented mongrel)

Alternate web servers (lighthttp, nginx, swiftiply)Alternate load balancers (pen, pound, balance, haproxy,hardware)

Alternate Ruby implementations (JRuby, Rubinius)


Introduction

RubyRails


Conclusion


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Further Reading

Download the presentation (pdf and tex) athttp://polibyte.com

Find related materials tagged as IT854 on del.icio.us

Deploying Rails Applications by Ezra Zygmuntowicz, BruceA. Tate and Clinton Begin

Agile Web Development with Rails by Dave Thomas and

DHH



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Ill stick around for questions.

Macworld 2008 - IT854 - Riding the Rails on OS X

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