© 2010 SpringSource, A division of VMware. All rights reserved© 2010 SpringSource, A division of VMware. All rights reserved

Hands On Open Source Development

Dr. Mark Pollack

Sr. Staff Engineer: SpringSource

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Introductions…

Who is this guy?

Who are you?

All about SpringSource and the Spring Framework

Project Goal: Build open source software

• Using ‘modern’ development processes and tools

Why should you care?

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Projects to develop

Portable “Blob” storage API

Data access library for the open source database CouchDB

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Blob project

“Cloud” data storage is where many individuals and companies store data.

• Your personal family pictures

• Internal audit trail logs

Several public providers of this fully managed service

• Amazon S3

• OpenStack

• Microsoft Azure

Host your own service on your own infrastrucutre.

• Eucalyptus

• Riak

10,000 ft project goals

• API ease of use for common cases

• API portability

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Data Access library for CouchDB

What is CouchDB

• Part of a new ‘wave’ of non-relational databases

• Open source Apache project

• Considered a ‘document’ database. Data is stored as a JSON document

• HTTP/REST requests to interact with the database

• “GET” – get a document

• “PUT - put a new document

• “DELETE” - delete a document

• …

• Query is done by creating ‘views’ on the document

• Specifically using “Map/Reduce” framework in JavaScript

10,000 ft. project goals

• Provide full Java API for all HTTP requests

• Simplify the storage of Java objects in the database

• Simplify querying the database for common cases

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Development Philosophy

Follow agile development principals

• Adherence to core OO design principals

• Decoupling, encapsulation, orthogonality

• Unit/Integration tests

• Rapid feedback on the impact of my own changes

• Continuous integration

• Rapid feedback on the impact of everyone else’s changes

• Iterations/Sprints/Intervals…

• “Stakeholder” feedback on the impact of changes

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Traditional and Agile software development approaches

Traditional

• Assumes change is avoidable

• Manage change by sufficient pre-planning and design to avoid change

• Big design up front

Agile

• Assumes change is inevitable and unavoidable

• Assumes impossible (or impractical) to plan-around change

• Ties to manage change by ensuring the software remainds flexible enough or respond to change

• Ensures that sufficient tooling, process and methods are in place to allow response to change within the context of an incredibly tight feedback loop

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Key Practice : Version control

Manages the source code across the team

• Mark known points in time for releases

We will also integrate source control with bug tracking

Version control is a requirement for Continuous Integration

Will use subversion for version control

• Central repository model

• You may have to handle merges when there are simultaneous changes to the same lines of code.

• Will be hosted at SpringSource

Will use “Fisheye” to browse code on the web

• See https://fisheye.springsource.org/browse

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Key Practice: Continuous Integration

Automated way to enable us to rapidly respond to change while continuing to have working software.

Software that constantly checks out code and does the following

• Compiles code

• Run unit/integration tests

• Run code metrics (optional)

• Deploy (optional)

And notifies you on failure…

We will use CI product “Bamboo”

• Setup for you already. See http://build.springsource.org/

• Just need to check email for notification

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Key Practice: Unit/Integration Testing

Developers write tests to ensure software behave as expected

May test an individual class in isolation (unit testing) or larger parts of the system collaborating together (integration testing)

• Both are important

Regression harness

• Feedback on code changes

• Allows code to be changed/refactored quickly, easily, and safely in response to change in requirement, architecture, etc.

• The quicker you find a bug, the cheaper it is to fix it

To follow this practice need to select a testing framework

• We will use JUnit inside Eclipse

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Key Practice: Bug, Issue, Project Tracking

Manage project goals for components, versions, timelines

“Issues” are entered into the system for new features

• Estimates made when to complete stories

“Bugs” entered to report bugs

In practice used to drive much of the reporting and status of the project

We will use JIRA

• See https://jira.springsource.org/secure/Dashboard.jspa

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Product documentation

Many ways to provide this, SpringSource has generally settled on DocBook

• XML schema defines book content. e.g. chapter, paragraph, etc.

XMLMind is a graphic semi WYSIWIG editor

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General flow

Discuss/teach tools/process at each meeting

We will have a planning session at the beginning of each meeting

• We will make goals, decide what’s required to achieve those goals, and the goals need to be measurable

• We will also talk about how well we did, what we could have done better, and what to do for the next iteration- retrospective

• We will also need to figure out the feasibility and estimate the time it will take to complete iterations

During iterations, if we have questions contact Mark via the mailing list.

2 week iterations so iterations cycle=meeting cycle

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Resources

“Big Picture” agile overview

• Agile Samuari – some free chapters (on estimation)

• Code Leader: Using People, Tools, and Processes to Build Successful Software

• Agile Estimating and Planning – Mike Cohn

• Agile Software Development, Principle, Patterns, and Practices – Bob Martin

• http://www.agilefirestarter.com/ Free conference material (pdfs)

• https://github.com/agilefire/November2010 (power poit)

Eclipse 3.6 or SpringSource Tool Suite 2.5.2

• http://eclipsetutorial.sourceforge.net/totalbeginnerlessons.html (videos!)

JUnit

• www.junit.org (note: JUnit is already integrated into eclipse)

• http://www.vogella.de/articles/JUnit/article.html

• http://pragprog.com/titles/utj/pragmatic-unit-testing-in-java-with-junit (book)

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Resources

Subversion

• http://subversion.tigris.org/

• Tortoise SVN - http://tortoisesvn.tigris.org/

• http://subclipse.tigris.org/ eclipse add-in

• http://svnbook.red-bean.com (free book)

• Pragmatic Version Control using Subversion (book)

DocBook

• http://www.docbook.org/

• http://www.xmlmind.com/xmleditor/

JIRA

• See videos/docs on http://www.atlassian.com/software/jira/

Continuous Integration (“Bamboo”)

• See videos on http://www.atlassian.com/software/bamboo/

• Continuous Delivery (book)

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Resources

CouchDB

• http://couchdb.apache.org/

• http://guide.couchdb.org/ (free book)

Amazon S3

• http://aws.amazon.com/s3/

• http://docs.amazonwebservices.com/AmazonS3/latest/gsg/

• http://www.sitepoint.com/books/cloud1/ book

• Before, many out of date and difficult to read books on AWS/S3 out there…

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Resources

Spring Framework

• http://en.wikipedia.org/wiki/Spring_Framework

• http://www.springsource.org/documentation

• Spring in Action V3 (book)

Spring RestTemplate

• http://blog.springsource.com/2009/03/27/rest-in-spring-3-resttemplate/

• Reference Manual

• RESTful Web Services (book)

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Fun for the weekend

Read the chapter on estimation in the Agile Samurai

• http://media.pragprog.com/titles/jtrap/estimate.pdf

Take a look at CouchDB/Amazon S3

• With an eye to see which project you want to develop.

If you are not familiar with Java/Eclipse/JUnit already start a bit with the following

Download latest Eclipse or SpringSource Tool Suite and get familiar with the environment

Follow the JUnit tutorial