Racker - Making Packer Templates Easier

This is a derivation of my previous Vagrant talk, including a more in depth presentation of why I developed Racker and how we use Racker at Yieldbot.

Transcript

1. Racker Making Packer Templates Easier Anthony Spring Chef-Boston Meetup - September 2014
2. What is Packer? “Packer is a tool for creating identical machine images for multiple platforms from a single source configuration.”
3. Why use Packer? Trust Repeatability Fast Flexibility
4. Packer 101
5. Variables Allows for specifying user defined configuration from the command line, environment variables or file.
6. Builders Define the high level configuration settings for the box that is getting built. DigitalOcean, Docker, EC2, GCE, OpenStack, QEMU, VirtualBox, VMWare
7. Provisioners A set of ‘scripts’ that get applied to each an image. Ansible, Chef Solo, File Uploads, Salt, Shell Scripts
8. Provisioner Script
9. Post Processors Determines the type of output artifact generated and where that artifact is placed. Docker Import, Docker Push, Vagrant, vSphere
10. Putting it all together Build several images in parallel. Target specific builders (inclusive/exclusive). Everything used to build the box is in source control. Its really freaking sweet!
11. Packer @ Yieldbot Primarily CentOS/RHEL Build universal images for Docker, EC2 AMI, VirtualBox, VMware ESXI, and VMware Fusion. Ability to provision with Chef Ability to test images before shipping
12. Evolution Created a single primary Packer template Change to the base template — required changes to all of its derivatives. Variables could only take us so far. Not very easy to merge the Packer JSON template format. Very difficult to comment JSON
13. What is Racker? An opinionated Ruby DSL for Packer templates
14. -Everyone “Why do we need another Ruby DSL?”
15. Racker Determinant merging of templates DRY templates Provide a method of knocking out hash values Ability to add comments Its just Ruby!
16. Racker CLI
17. Racker CLI at Work
18. Packer Snippet Racker Template
20. Baking Boxes with Chef Pre-load Chef provisioned assets Environment aware Let Racker do the work
21. Basic Chef Provisioner This gets applied to all boxes.
22. Deep Merge The base overlays the top and then the bottom to achieve the desired result.
23. Resulting Packer Template Properly defined and ordered run list.
24. It’s Just Ruby Backticks and all other fun stuff!
25. -Everyone in the audience “How do you manage all of these Racker templates?”
27. Planet Express “Make building and deploying boxes so easy a caveman could do it.”
28. Planet Express Caveman Easy
30. Box Build Statistics Metrics are always good!
31. What is grey matter? Grey matter is the area of your infrastructure where you have the least amount of confidence.
32. “Reducing grey matter is essential to increasing confidence.”
34. Another Chef Run Lets us decouple from any other Chef configuration.
35. ServerSpec Guts Prep the environment for ServerSpec Upload Rakefile, Gemfile, etc. Upload individual specs Run the specs Cleanup
36. Upload spec(s) as needed This allows us to easily reuse the Racker template per box.
37. Kickstart Small portion of a Kickstart file
39. How will you use Racker?
40. Credits http://www.packer.io/ https://github.com/misheska/basebox-packer https://github.com/garethr/packer-serverspec-example https://github.com/aspring/racker
41. Anthony Spring Minister of DevOps Culture aspring@yieldbot.com @devopsanthony The opinions expressed here represent my own and not those of my employer.