building better chef community cookbooks

Tim Smith - @tas50 Community Engineer, Chef

Building Better Community Cookbooks

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Let’s Start With a Little Story

Hypothetical Sysadmin

New to Chef

New to Ruby

New to this DevOps thing

Lets call him 2011 Tim

New to Chef

New to Ruby

New to this DevOps thing

Hypothetical Sysadmin

Tim’s first community cookbook experience

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My Boss Circa 2011

We need a monitoring system. Go build one and

have it done… this week!

Couldn’t be that hard….

Chef Will Solve Everything

Maybe not…

Oh Wait No RHEL Support

Time to get hacking

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Time to get hacking

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This is basically what ruby looked like to me

Way Too Much Time Later

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By week you meant month right?

Way Too Much Time Later

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Where are all my nodes?

Hardcoded EVERYTHING!

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Hardcoded Chef searchesHardcoded Chef environments to ignore

Hardcoded Nagios service checksHardcoded Nagios service groups

Just about everything else…hardcoded

A lot of commits later

In the end we had a great cookbookbut the project was a failure

So what did I learn from all this?

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Community cookbooks are a tire fire right?

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NoIt’s more complicated than that

3000+ Cookbooks7000+ Users

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Some are Great. Some not so much.They All Solved Someone’s Problem Though

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Some cookbooks are community cookbooks; others are just shared code

https://www.flickr.com/photos/huangjiahui/2893120846

How do we write community cookbooks and not shared code?

https://www.flickr.com/photos/wlodi/3152672560

Community cookbooks are not enterprise cookbooks

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CommunityCookbook

EnterpriseCookbook

Usage Pattern, Platform Support, Tuneables, etc

Community cookbooks provide well tested and simple interfaces to

composable resources that empower users to write their own

cookbooks which aid in the automation of highly customized

and complex software environments

S

W

A T

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Simple Interfaces

Wrappable

All platforms supportedTested thoroughly

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Simple Interfaces

W

A T

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Technology is hard. Your cookbook shouldn’t be harder

Interface Patterns to Avoid

Large numbers of attributes

Clever abstraction models only you understand

Trying to parameterize the impossible

Understanding Simple Interfaces

Components of a Simple Cookbook

App Binary

Config

Service Management

App Binary

Config

Service Management

Components of a Complex Cookbook

Cookbook components map to Custom Resources nicely

App Binary

Config

Service Management

foo_install

foo_config

foo_service

Component to Custom Resource Mapping

Don’t jump into code. Write test recipe firstThat’s your design

Think about how YOU would want to consume the resources

It’s the hard right thing

Example Test Recipe

S

Wrappable

A T

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Turn key cookbooks never work2011 Opscode lied to you

Design Patterns to Avoid

Highly opinionated end to end cookbooks

Monolithic recipes (or recipes altogether)

Opinionated dependency installs (ruby, java, etc)

Sample Wrapper Usage PatternsGood and Better Designs

Basic Wrapper

Better Wrapper

S

W

All platforms supportedT

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All Platforms Supported

Someone somewhere is going to want Gentoo support

Richard Stallman…loves that laptop apparently

S

W

A Tested thoroughly

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Do you test your changes?On every platform?

Every single commit?

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You need automated testing

What to test though?

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Cookstyle/Foodcritic

ChefSpec

Test Kitchen / InSpec

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Tim’s Hierarchy of Testing Usefulness

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Cookstyle

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Foodcritic

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ChefSpec

Don’t Test Chef

Test Your Cookbook Logic

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Test Kitchen

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Great but takes forever

Kitchen Dokken

https://github.com/someara/kitchen-dokken

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InSpec

Please don’t just test ChefTest what’s important to your app

Simple Interfaces

Wrappable

All platforms supportedTested thoroughly

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Resources for help

https://www.flickr.com/photos/120920526@N08/15094478519

sous-chefs.org

Fresh New Chef Stuff on Youtube

Chef Community Slack

CfgMgmtCamp TalksMonday● Containers 14:00 - Monoliths, Myths, and Microservices

● Containers 16:20 - An upside-down Exploration of App Automation with Habitat

● Chef Room - 14:00 - Chef - Ask Me Anything (AMA)

● Chef Room - 14:40 - An Open-Source Chef Cookbook CI/CD Implementation Using Jenkins Pipelines

● Chef Room - 15:40 - What's coming in Chef 13

● Chef Room - 16:20 - Building Better Community Cookbooks

● Chef Room - 17:00 - Chef, Microsoft, and Open Source: State of the Nation

Tuesday● Main Track 14:00 - Operating Systems are Assholes

● Future Tooling - 14:40 - Now That I Have Choreography, What Can I Do With It?

● Chef Room- 14:00 - Shared Services is Not a Field of Dreams

● Chef Room - 14:40 - CI/CD Workflows at Enterprise Sports Scale

● Chef Room -How to get the most of Foreman and Chef

● Main Track 16:20 - Food Fight Show