AWS CloudFormation Templates

AWS CloudFormation is AWS's own Infrastructure as Code service. A CloudFormation template is a file — commonly written in YAML — that describes the AWS resources that should exist. Submitting a template to CloudFormation creates a stack: the deployed, managed collection of actual AWS resources described by that template.

Here is a deliberately minimal, fictional training example:

AWSTemplateFormatVersion: '2010-09-09'

Description: QuarryDev training example

Resources:
  TrainingBucket:
    Type: AWS::S3::Bucket

Reading this: AWSTemplateFormatVersion identifies the template-format syntax being used (this is a fixed value tied to CloudFormation's template format itself, not a claim about current AWS product versioning). Description is a human-readable label. Resources is where the actual infrastructure is defined — here, one fictional S3 bucket named TrainingBucket, of type AWS::S3::Bucket.

A brief note on reading the YAML itself: indentation indicates nesting (everything under Resources, indented further, belongs to it), and Key: Value pairs describe properties — that's enough YAML to follow every example in this module, without needing to learn YAML as its own subject.

A template can include other sections — Parameters and Outputs, covered in depth next lesson, and Mappings/Conditions for more advanced scenarios this module doesn't need — but Resources is the one section every useful template needs, since it's what actually defines the infrastructure.