IAC / A CONCEPT NOTE
Infrastructure as Code
managing infrastructure through machine-readable definition files
Overview · mechanism
pitfall · examples
01 / THE SHORT VERSION
The idea in a few sentences.
Instead of clicking in a web console, you write configuration files (HCL for Terraform, YAML for CloudFormation, TypeScript for Pulumi) that declare your infrastructure. These files are version-controlled, code-reviewed, tested, and applied through automation. The cloud provider's API is the only interface — no manual steps.
02 / FOLLOW THE MECHANISM
How iac changes the game
You
write a config file describing a VPC, subnets, EC2 instances, and an RDS database.
CI
runs
terraform planorpulumi previewin the PR for peer review.Engine
computes the diff between the current state (from state file) and the desired state (from config).
Apply
executes the necessary API calls to converge real-world resources to the config.
04 / COMMAND NOTES
Read the command, then the result.
Inspect the flags and arguments before trying an example. Snippets can need local setup, replacement values, or resources in your own environment.
preview changes before applying
terraform plansee what Pulumi would change
pulumi preview05 / CHECK YOURSELF
Could you explain Infrastructure as Code to a teammate?
Try it out loud in two sentences: what it is, and the one detail that changes the picture. If you stall, the gap is the part to reread.
Up next in Infrastructure as codePulumiinfrastructure as code using real programming languages