chefconf 2016 - writing compossible community cookbooks using chef custom resources

Tim Smith - @tas50 Community Engineer, Chef

Writing Compossible Community Cookbooks using Chef Custom Resources

A Community Cookbook Origin Story

https://www.flickr.com/photos/pesotum/171923662

Ops we need MyFace deployed by

end of day!

https://upload.wikimedia.org/wikipedia/commons/9/9a/Meeting_in_Air_Force_One_conference_room.jpg

http://joebideneatsicecream.tumblr.com/

No worries Ill whip it up in Chef

Salt and Straw is way expensive

https://en.wikipedia.org/wiki/Cycling#/media/File:Leon_Georget_1909.jpg

v1.0: Simple and Elegant Design

https://www.flickr.com/photos/christopheducamp/7463696734

I Should Share This!

http://www.slate.com/content/dam/slate/articles/news_and_politics/politics/2015/05/150519_POL_MissionAccomplished.jpg.CROP.promovar-mediumlarge.jpg

https://pixabay.com/en/clock-wall-clock-brick-wall-old-1250204/

https://upload.wikimedia.org/wikipedia/commons/thumb/6/69/Richard_Stallman_by_Anders_Brenna_03.jpg/1280px-Richard_Stallman_by_Anders_Brenna_03.jpg

Time to Put On My Maintainer Hat

Things Are About to Get Weird

https://en.wikipedia.org/wiki/Penny-farthing#/media/File:Pennyfarthing-1886.jpg

https://en.wikipedia.org/wiki/Smoke_screen#/media/File:2010_0515_rama_4_and_sathorn_22a.JPG

https://en.wikipedia.org/wiki/Smoke_screen#/media/File:2010_0515_rama_4_and_sathorn_22a.JPG

Database cookbook

How Do We Right the Ship

https://upload.wikimedia.org/wikipedia/commons/b/b6/Cougar_Ace_on_side_%28starboard_side%29.jpg

Scrap it and Start Over

Apache Tomcat

Quick Sidebar

Oh Geez Not Tomcat?

I hate Java!

All the cool kids write JS

https://www.flickr.com/photos/jamescridland/613445810


Me


MeYou


Blah BlahTomcat Blah Blah Blah Blah Blah Blah



Node



Node Rust

Web Stuff

JAVA XML

pixabay.com & Wikimedia Commons

Tomcat 101

http://pixabay.com

End Sidebar(I told you itd be quick)

Why is Tomcat Such a Great Example

https://pixabay.com/en/cat-siberian-tomcat-1086330/

https://pixabay.com/en/ruins-pretoria-building-stones-664869/

It Was Completely Falling Apart

https://www.flickr.com/photos/bitterjug/7670055210

It Attempted to Automate Complex Software

pixabay.com

It Used a Rigid Monolithic Design

Matt Groening

It Followed the Natural Cookbook Progression

https://upload.wikimedia.org/wikipedia/commons/7/79/Operation_Upshot-Knothole_-_Badger_001.jpg

Nuke it and Start Over Right?

https://www.flickr.com/photos/39908901@N06/13963173985

Nope. Lets Think This Through

What should a community cookbook look like?

Community Tomcat vs. In House Tomcat Cookbook Scope

Pre-rewrite Checklist

What are the building blocks of a Tomcat Cookbook?

Whats the Job of a Community Cookbook Anyways?

https://static.pexels.com/photos/56002/pexels-photo-56002.jpeg

Provide simple interfaces to compossible resources that empower users to write their own cookbooks which aid in the automation of

highly customized and complex software environments

Source: Me

Community cookbooks should:

simple interfaces

https://en.wikipedia.org/wiki/History_of_Lego#/media/File:Lego_dublo_arto_alanenpaa_5.JPG

compossible resources

https://pixabay.com/en/lego-lego-duplo-building-built-190704/

empower users to write their own cookbooks

https://www.flickr.com/photos/mr_t_in_dc/4766284256

highly customized and complex software environments

https://pixabay.com/en/lego-legoland-legostadt-186034/

Community Tomcat vs. Private Tomcat Cookbook Scope

https://commons.wikimedia.org/wiki/File:2_duplo_lego_bricks.jpg

MyCorp Tomcat Community Tomcat

Usage pattern Opinionated Flexible

Platform Support Single Platform (usually) Multi-platform

Tuneables Limited Every possible thing


https://en.wikipedia.org/wiki/Lego#/media/File:Lego_Color_Bricks.jpg

App Binary

Config

Service Management

Components of a Simple Cookbook

App Binary

Config

Service Management

tomcat_install

tomcat_config?

tomcat_service

Component to Custom Resource Mapping

tomcat_install scope

Fetch artifact Specify a version Install artifact to directory Set user / group permissions on the install

Time to Generate the Cookbook

Even More Important

Install Your App Binary

tomcat_config scope

Allow passing a monolithic XML config blob in via Ruby.

Pretty sure this isnt possible. Good PRs accepted!

Test Recipe is Your Design

tomcat_service scope

Install init script / config Allow start/stop/restart/enable actions on the service Work with sys-v, upstart, systemd init

Define Your Service

Put it All Together

Custom Resource Time

https://en.wikipedia.org/wiki/Lego#/media/File:Lego_Color_Bricks.jpg

Basic Custom Resource

Properties: Variables you pass in

Actions: One or more things the resource can do

Provides: Name of the resource and a distro to run it on (optional)

Action Class: Helper methods for use in the actions (optional, but handy)

Create the Resource

Example of Properties

Example of Actions

Example of Action Class

Example of Provides

service_sysv_init.rb

service_upstart.rb

service_systemd.rb

tomcat_service to Init Mapping

RHEL < 7 Amazon Linux SUSE < 13 Debian < 8

Ubuntu < 15.10

Debian 8+ SUSE 13+ Ubuntu 16.04+ RHEL 7+ Fedora

Provides is Magic

http://i.bullfax.com/imgs/3d20fd81ba73b7479088e77b363a5a1e690b3e52.jpg

Platform Support is Done!


Oh We Forgot That One Platform


PRs Welcome

one more thing

https://upload.wikimedia.org/wikipedia/commons/4/47/StateLibQld_1_100348.jpg

Lets Test This Thing

https://en.wikipedia.org/wiki/Runway_(fashion)#/media/File:ModelsCatwalk.jpg

Cookstyle

http://a.fod4.com/images/user_photos/1356028/cea985e2ee743a14e6f466860b082381_width_640x.jpg

Foodcritic

https://www.flickr.com/photos/ell-r-brown/20267645405/in/photostream/

InSpec

Simple Inspec Tests

Test Kitchen To Tie It All Together

Test It All

Kitchen-dokken in Travis CI is Also Magic

Design

Test Cookbook

Resources

Testing

Awesomeness

Read the Docs For More Cool Stuff

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

https://docs.chef.io/custom_resources.html

chefconf 2016 - writing compossible community cookbooks using chef custom resources

Technology