Heroku Cloud Application Development

Anubhav Hanjura

• Publisher: Packt Publishing
• Year: 2014
• ISBN:
  9781783550975
• Edition: 1
• Topic: Computer Science
• Subtopic: Systems Architecture
• Index: Computer Science

In Detail

Heroku is one of the leading cloud platform-as-a-service technologies that aims to help you deploy feature-rich web apps with Elan. It supports several widely popular programming languages like Ruby, Java, PHP, and Python to name a few, and also offers support for multiple data sources (sqllite and postgres). Heroku is all about ease of deployment and application management, as it lets you build and run web apps without having to worry about the servers.

This book is about Heroku but more importantly, it is about the ease with which a developer with limited availability or knowledge of deployment infrastructure can run and manage a cloud app 24/7/365. It will show how Heroku is language independent and does not lock the user to a particular operating environment, giving users the flexibility of choosing the right software infrastructure based on the scale of the app hosted.

This books starts by unraveling the basics of the Heroku stack. The book then moves on to teach you simple steps to build and deploy an app on Heroku. You will also experience the ease of running and troubleshooting a Heroku app.

The book illustrates the process of creating a new web application with Heroku. Along the way, you will also learn some advanced topics such as configuring Heroku with web sockets, monitoring your apps, and managing your DNS for Heroku. The book will also detail the process of building custom build packs to support for other languages, how to enable Heroku for mobile apps and much more. This book will demonstrate the security processes in Heroku, enabling you to enforce tighter controls at every layer of the platform.

This book will help you build cloud applications the right awaythe first time and every timeas well as scale Heroku to achieve high availability and fine-tune the Heroku infrastructure.

Approach

An easy-to-follow, hands-on guide that clearly explains the various components of the Heroku platform and provides step-by-step guidance as well as numerous examples on how to build and troubleshoot robust and scalable production-ready web applications on the Heroku platform.

Who this book is for

This book is intended for those who want to learn Heroku the right way. Perhaps you are new to Heroku or are someone who has heard about Heroku but have not built anything significant with it. You should have knowledge or familiarity with cloud computing and basic knowledge of database and network deployment.

Heroku Cloud Application Development

---

Table of Contents

Heroku Cloud Application Development

Credits

About the Author

About the Reviewers

www.PacktPub.com

Support files, eBooks, discount offers and more

Why Subscribe?

Free Access for Packt account holders

Preface

What this book covers

What you need for this book

Who this book is for

Conventions

Reader feedback

Customer support

Errata

Piracy

Questions

1. Hello Heroku

What is cloud computing?

Cloud service models

What is cloud application development?

Key advantages of cloud application development

Introducing Heroku

Walking down the memory lane

An overview of Heroku's architecture

Process management

Logging

HTTP routing

Heroku interfaces

The Heroku feature set

Let's play Heroku

Getting ready for the ride – the prerequisites

Signing up

Installing the Heroku toolbelt

Logging in and generating a new SSH key

Test driving Heroku

Summary

2. Inside Heroku

The Heroku platform stack

The Celadon Cedar stack

Request routing in Heroku

The execution environment - dynos and the dyno manifold

Heroku's logging infrastructure – the Logplex system

The Heroku add-on architecture

Programmatically consuming Heroku services

The Heroku Platform API

Security

Schema

Data

Accessing the API

API clients

Calling the API

Response

Limits on API calls

The Heroku process architecture

Procfile

Declaring process types

The Procfile format

A sample Procfile

Adding Procfile to Heroku

Running applications locally

Setting local environment variables

Process formation

Process scaling

Stopping a process type

Checking on your processes

Process logs

Running a one-off process

Running anything

Summary

3. Building Heroku Applications

Heroku's guiding influence – the Twelve-Factor App methodology

A codebase is always versioned and it can have multiple deploys

Declare and isolate dependencies explicitly (always)

Configuration should be stored in the environment

Backend services should be treated as attached (loosely-coupled) resources

Strict separation of the build, release, and run stages of an app

An app in execution is a process or many processes

Services should be exported through port binding

An app should scale out through its process model

Faster startup and graceful shutdown is the way to app agility and scalability

Development and production (and everything in between) should be as similar as possible

The app should just log the event not manage it

App's administrative or management task should be run as a one-off process

Creating a Heroku application

Configuring your Heroku application

The Heroku application configuration API

Examples of using application configuration

The persistence of configuration variables

Accessing configuration variables at runtime

Limits on configuration data

Using the Heroku config plugin

Introducing buildpacks

Using a custom buildpack

Specifying a custom buildpack at the app creation stage

Third-party buildpacks

The buildpack API

Components of a buildpack API

The bin/detect script

The bin/compile script

The bin/release script

Writing a buildpack

The slug compiler

Optimizing the slug

Size limits

Summary

4. Deploying Heroku Applications

Deployment on Heroku

Getting a Heroku account

Installing the toolbelt client kit

Logging into the Heroku account

Setting up SSH

Writing your application

Pushing your application to Heroku

The Git vocabulary

Getting started with Git

Tracking a new project

Using an existing Git project

The life cycle of an artifact in Git

Tracking files in a Git project

When you don't need Git to track your files

The git diff command – knowing what changed

Committing your changes

Deleting a file

Moving a file

Viewing commit history

Undoing a change

You can use some Git help

The local repository

Remote repositories

Creating a Heroku remote

Renaming an application

Sending code to Heroku

Optimizing slug size

Cloning existing Heroku applications

Forking an application

Side effects of forking an application

Transferring Apps

Optimizing deployments

The choice of a region

Tracking application changes

Setting up Deploy Hooks

Basecamp

Campfire

E-mail

HTTP

IRC

Release management

Checking installed releases

Verifying the new release

Rolling back the release

Summary

5. Running Heroku Applications

The Heroku app lifecycle

The Heroku CLI

How to get the Heroku client tool

Verifying the tool

How to get the latest Heroku client tool

Where is the Heroku client stored?

What if my client installation is corrupted or not working?

The Heroku CLI commands

Heroku CLI commands by function

Extending the Heroku CLI

The Heroku CLI and add-ons

A note on Heroku CLI and security

Running your cloud apps locally

Using Foreman to check Procfiles

Using Foreman to run apps directly

Running one-off commands

Foreman command-line options

The Apps page

The Resources tab

Managing resources

The Activity tab

The Access tab

The Settings tab

The Run Production Check tab

Heroku support

Summary

6. Putting It All Together

Heroku's support for Java

General support for Java

Database support for Java apps

Environment configuration

Integrating Eclipse with Heroku

Prerequisites

Configuring Heroku in Eclipse

Installing the Eclipse plugin for Heroku

Setting up Heroku for development

Setting up SSH support

Creating a new Heroku Java app in Eclipse

Using an existing Heroku appli...

Table of contents

• Heroku Cloud Application Development