Getting Started with OpenShift: A Guide for Impatient Beginners

by Steve Pousty, Katie Miller

Overview

Intrigued by the possibilities of developing web applications in the cloud? With this concise book, you get a quick hands-on introduction to OpenShift, the open source Platform as a Service (PaaS) offering from Red Hat. You’ll learn the steps necessary to build, deploy, and host a complete real-world application on OpenShift, without having to read long, detailed explanations of the technologies involved.

Though the book uses Python, application examples in other languages are available on GitHub. If you can build web applications, use a command line, and program in Java, Python, Ruby, Node.js, PHP, or Perl, you’re ready to get started.

• Dive in and create your first example application with OpenShift
• Modify the example with your own code and hot-deploy the changes
• Add components such as a database, task scheduling, and monitoring
• Use external libraries and dependencies in your application
• Delve into networking, persistent storage, and backup options
• Explore ways to adapt your team processes to use OpenShift
• Learn OpenShift terms, technologies, and commands
• Get a list of resources to learn more about OpenShift and PaaS

Product Details

ISBN-13:	9781491904718
Publisher:	O'Reilly Media, Incorporated
Publication date:	05/14/2014
Sold by:	Barnes & Noble
Format:	eBook
Pages:	104
Sales rank:	732,135
File size:	2 MB

About the Author

Steve is a Dad, Son, Partner, and PaaS Dust Spreader (aka developer evangelist) with OpenShift. He goes around and shows off all the great work the OpenShift engineers do. He can teach you about PaaS with Java, Python, PostgreSQL MongoDB, and some JavaScript. He has deep subject area expertise in GIS/Spatial, Statistics, and Ecology. He has spoken at over 50 conferences and done over 30 workshops including Monktoberfest, MongoNY, JavaOne, FOSS4G, CTIA, AjaxWorld, GeoWeb, Where2.0, and OSCON. Before OpenShift, Steve was a developer evangelist for LinkedIn, deCarta, and ESRI. Steve has a Ph.D. in Ecology from University of Connecticut. He likes building interesting applications and helping developers create great solutions.

Katie Miller, also known as codemiller, works as an OpenShift Developer Advocate at Red Hat. Katie is a polyglot programmer with a penchant for Haskell. The functional programming enthusiast co-founded the Lambda Ladies online community and co-organizes the Brisbane Functional Programming Group. Katie is a familiar face at an array of Meetup groups spanning a variety of programming language communities, including Java, JavaScript, Python, and Ruby. The former newspaper journalist has presented at conferences and Meetups across Australia and New Zealand and as far afield as Budapest, Hungary. Katie is passionate about coding, open source, software quality, languages of all kinds, and encouraging more girls and women to pursue careers in technology.

Table of Contents

Preface vii

1 Introduction 1

What Is the Difference Between IaaS, PaaS, and SaaS? 1

The Three Versions of OpenShift 2

Choosing the Right Solution for You 3

Things to Understand 4

Words You Need to Understand 4

Technology You Need to Understand 5

2 Creating Applications 9

Preliminary Steps 9

Setting Up the Command-Line Tools 9

Creating Your First Application 11

Autoscaling and Why You Should Use It by Default 14

Reasons to Move to the Paid Tier 15

3 Making Code Modifications 17

Cloning Code to Your Local Machine 17

Modifying Application Code 18

Building and Deploying Your Code 20

Action Hook Scripts 21

Hot-Deploying Code 22

4 Adding Application Components 25

Database-Related Cartridges 25

Nondatabase Cartridges 27

Cron 27

Continuous Integration 29

Metrics and Monitoring 31

Finding Cartridges and QuickStarts 32

Adding Third-Party Cartridges 35

5 Environment and Application Management 37

SSH Access 37

Using SSH to Interact with a Database 39

Importing SQL in an SSH Session 40

Environment Variables 41

Precontigured Environment Variables 41

Custom Environment Variables 42

Overriding Preconfigured Environment Variables 43

Log Access 43

Changing Application Server or Database Settings 44

Application Server Configuration Changes 44

Database Configuration Changes 45

Using Marker Files 45

6 Library Dependencies 47

Where to Declare Dependencies 47

Incorporating Your Own Binary Dependencies 49

Modifying Your Application to Use the Database 50

Code to Connect to the Database 50

Code to Close the Database Connection 51

Code to Query the Terms for the Insult 51

What We Have Gained by Adding a Database 52

7 Networking 53

WebSockets 53

SSH Port Forwarding 55

Custom URLs 57

SSL Certificates 59

Talking to Other Services 60

Addressable Ports 61

8 Disk Usage 65

Where You Can Write "to Disk" 65

Determining How Much Disk Space Is Used 66

Copying Files to or from Your Local Machine 67

Other Storage Options 68

9 Backup 69

Managing Deployments and Rollbacks 69

Manual Deployments 69

Keeping and Utilizing Deployment History 70

Application Snapshots with RHC 71

Backing Up Your Database 73

Writing a Cron Script 73

Moving Data off the Gear 74

10 Team Coilaboration 77

Managing Multiple SSH Keys 77

Domain Access for Teams 78

Possible Workflows 79

11 Summary 81

What We Covered 81

Other Areas to Explore 82

Final Words 83

A Basic Linux for Non-Linux Users 85