This document summarizes a meetup about infrastructure as code. It discusses the differences between treating infrastructure as "pets" versus "cattle", where pets are cared for individually and cattle are treated as disposable. When infrastructure is coded declaratively using tools like Terraform, the infrastructure can be version controlled, updated continuously, and rolled back like code. The meetup demonstrated setting up infrastructure on Azure using Terraform to define resources like virtual machines in code. Advanced techniques like storing state remotely and using modules were also discussed.

1. Post HashiConf EU Meetup 07/11/2019
Amsterdam

2. Julien Corioland
• Senior Software Engineer @ Microsoft
• Paris, France
• https://blog.jcorioland.io
• https://github.com/jcorioland
• https://twitter.com/jcorioland

3. Infrastructure as Code
Think about immutable and disposable infrastructure.

4. Pet vs Cattle
Pet Model
• You care so much about
your infrastructure that you
give it lovely names
• Earth, Jupiter, Mars …
• Goals: each server part of
your infrastructure should
be up 24/7
Cattle Model
• You stop naming your
servers and consider it as
“disposable” infrastructure
• front-01, front-02, front-
03…
• Goals: n servers are part of
the infrastructure 24/7

5. Cloud platforms make it possible
All is about automation
Imperative (Bash/PS scripts)
Declarative (ARM, Terraform…)
Idempotency

6. Infrastructure = code
• Stored in the source code repository
(GitHub, Azure Repos…), it’s just text!
• Same lifecycle
• You update the code, you update the
infrastructure
• Continuous Integration / Continuous
Deployment
• Versioning
• Labels / Rollbacks
• Also valid for configuration (configuration as
code)

7. Terraform
Write, Plan, and Create Infrastructure as Code

8. What is Terraform?
• An open source tool/language (HCL) developed by HashiCorp
• Allows to write, plan and create infrastructure as code
• Common language for different providers
• Azure
• AWS
• Google
• Kubernetes
• …
• Same workflow / pipeline
• But different resources!

9. Data Sources
& Resources

10. Terraform
Workflow
Init
Plan
Apply
Destroy

11. Demonstration
Hello Terraform on Azure!

12. Advanced Workloads
• Remote State Storage
• Use Azure Storage or Terraform Cloud as backend
• Share states between teams and CI/CD runs
• Terraform Modules
• Module = container for multiple resources that are used together
• Automated testing
• How do I continuously integrate Terraform Infrastructure as Code ?

13. Demonstration
Terraform on Azure – Reference Architecture
https://github.com/jcorioland/terraform-azure-reference

14. Questions/Follow up
Julien Corioland
@jcorioland