A complete guide to building and deploying web apps with
Heroku

A cloud application platform, Heroku is currently the only
approved platform for creating apps within Facebook, and its number
of users is growing at rapid pace. However, there are very few
books on the market that offer professional-level coverage of this
platform, until now. The author duo begins with an introduction to
the Heroku platform and its associated core concepts and then goes
on to explain how writing for this platform differs from that of
traditional development systems. Example applications, additional
resources, and advice for your next steps round out this resource,
making it a thorough, indispensable guide.

* Features information not found anywhere else, as both authors
work for Heroku

* Explains the inner workings of Heroku with special emphasis
placed on building web and mobile applications

* Introduces GIT-based development workflow and the process model
within the Heroku platform

* Details coding, building, deploying, and scaling effectively
using the Heroku tool base

Providing you with fully functional code and downloadable code
examples, Professional Heroku Programming is your complete
guide to mastering this platform.

Chris Kemp is on the Salesforce.com Advanced Technical Solutions team. He is the global leader of the Heroku expert group and is generally acknowledged to be one of the leading Heroku experts at Salesforce.com.

Brad Gyger is the Manager of the Customer Advocacy Team at Heroku. He and his team are tasked with ensuring that all users are able to optimize their experience on the Heroku platform.

A complete guide to building and deploying web apps with Heroku

A cloud application platform, Heroku is currently the only approved platform for creating apps within Facebook, and its number of users is growing at rapid pace. However, there are very few books on the market that offer professional-level coverage of this platform, until now. The author duo begins with an introduction to the Heroku platform and its associated core concepts and then goes on to explain how writing for this platform differs from that of traditional development systems. Example applications, additional resources, and advice for your next steps round out this resource, making it a thorough, indispensable guide.

• Features information not found anywhere else, as both authors work for Heroku
• Explains the inner workings of Heroku with special emphasis placed on building web and mobile applications
• Introduces GIT-based development workflow and the process model within the Heroku platform
• Details coding, building, deploying, and scaling effectively using the Heroku tool base

Providing you with fully functional code and downloadable code examples, Professional Heroku Programming is your complete guide to mastering this platform.

INTRODUCTION xxv

PART I: AN OVERVIEW OF HEROKU

CHAPTER 1: HOW HEROKU WORKS 3

How the Stacks Stack Up 4

Understanding Dynos and the Dyno Manifold 6

Understanding Dyno Isolation 8

Exploring the Process Model 8

Understanding Erosion Resistance 10

Managing Version Control 11

Understanding the Slug Compiler 12

Routing HTTP Requests 13

Summary 15

CHAPTER 2: ARCHITECTURAL CONSIDERATIONS 17

Building Twelve-Factor Applications 18

Managing Your Application Portfolio with Pace Layering 21

Systems of Record 21

Systems of Differentiation 21

Systems of Innovation 22

Classification 22

Security and Reliability 22

Governance 23

Application Portfolio Management 23

Ensuring Security and Compliance 25

Physical Security and Safeguards 25

Network Security 25

Dyno- and Stack-Layer Security 26

Data Retention 27

Dealing with Security Issues 27

Certifications, Accreditations, and Compliance 27

Understanding Redundancy and Reliability 28

Disaster Recovery and Availability Zones 28

Availability and Transparency 29

Securing Your Heroku Application 31

Use a Strong Password for Your Heroku Account 31

Encrypt All Data in Transit 32

Encrypt Sensitive Data at Rest 32

Use Best Practices for Secure Development 32

Don't Reinvent the Wheel 32

Verify Security and Compliance Needs with

Third-Party Providers 32

Monitor Your Application's Logs 33

Encrypting Communications with SSL 33

Piggybacking on Heroku's SSL Certificate 33

Using SSL Endpoint 34

Storing Static Assets and Using CDNs 36

Storing Static Assets on Amazon S3 36

Speeding Up International Applications with Amazon CloudFront 41

Summary 43

CHAPTER 3: PORTING YOUR APPLICATIONS TO HEROKU 45

Understanding Differences from Traditional Filesystems 46

Ephemeral Filesystems 47

Multi-Dyno Applications 47

Considerations for Porting Existing Applications 47

Choosing a Data Store 48

Using Heroku Postgres as a Data Store 48

Using Database.com as a Data Store 49

Using Add-On Data Stores 50

Using a Third-Party Data-as-a-Service Provider 50

Using Multiple Data Stores 51

Considerations for Porting Existing Applications 51

Managing Sessions 51

Understanding Caching 52

Storing Static Assets 54

Managing Configuration Variables 54

Replacing Web Servers and Containers 55

Managing Dependencies 56

E-Mailing from Your Application 57

Running Cron Jobs 57

Understanding Logging 59

Relying on External Programs 61

Scaling Up versus Scaling Out 62

Binding to Ports 62

Managing Long-Running Processes 63

Shutting Down Gracefully 65

Moving Your Domain 66

HTTPS over SSL 66

Considerations for Porting Existing Applications 67

Summary 68

PART II: CREATING AND MANAGING HEROKU APPLICATIONS

CHAPTER 4: DEPLOYING YOUR APPLICATIONS TO HEROKU 73

Installing the Heroku Toolbelt 73

Git 74

Foreman 75

The Heroku Client 76

Interacting with Heroku via the Command-Line Interface 77

The Magic of git push 79

Post Deploy Hooks 80

Navigating the Heroku Dashboard 80

Changing Your Application's Name 82

Adding Custom Domains 83

Adding Custom Collaborators 83

Scaling Resources 84

Summary 87

CHAPTER 5: MANAGING RELEASES WITH HEROKU 89

Managing Multiple Environments 90

Managing Configuration Variables 94

Securing Development Environments 97

Versioning and Rolling Back Releases 100

Using Deploy Hooks 102

Managing Planned Downtime and Custom Error Pages 103

Implementing Continuous Integration 107

Summary 114

CHAPTER 6: WORKING WITH ADD-ONS 115

The Heroku Add-On Ecosystem 116

Architectural Considerations 117

Exploring Popular Add-Ons 117

SQL-Based Data Stores 118

NoSQL-Based Data Stores 118

Search 119

Logging and Monitoring 120

Installing Add-Ons 121

Installing Add-Ons from the Heroku Dashboard 122

Installing Add-Ons from the Command-Line Interface 125

Creating Add-Ons 127

Summary 131

CHAPTER 7: MANAGING, MONITORING, AND SCALING YOUR HEROKU APPLICATIONS 133

Adding Custom Domains 133

Viewing Logs and Associated Tools 136

Managing and Tuning Performance 140

Performance Management with New Relic 141

Performance T…