CLD120 Module 10 — Automating Your Architecture

Module Objective

Automate the provisioning and management of a cloud architecture using infrastructure as code and AWS management tools.

Modules 3–8All layers✓ built

Module 9Elasticity & HA✓ done

Module 10Automationyou are here

Module 11Caching

Module 12Decoupling

Module 13Serverless

Module 14Disaster recovery

Builds on Module 9: elasticity and high availability depend on infrastructure that can be provisioned and reproduced automatically.

Infrastructure as Code

Infrastructure as code (IaC): define VPCs, EC2 instances, RDS databases, and IAM roles in a version-controlled template instead of clicking through the console.

Manual Provisioning	Infrastructure as Code
Steps are undocumented unless written down separately	The template itself is the documentation
Hard to reproduce identically in another Region or account	Deploy the same template anywhere
Configuration drift is easy to introduce	Re-deploying the template corrects drift

Note: IaC directly implements the Operational Excellence pillar’s “perform operations as code” principle (Module 2).

AWS CloudFormation

Concept	What It Means
Template	JSON/YAML file describing desired resources and their configuration
Stack	Resources created and managed together from one template
Change set	A preview of what a template update would actually change, before applying it

AWSTemplateFormatVersion: "2010-09-09"
Description: Example - cafe website bucket
Resources:
  CafeWebsiteBucket:
    Type: AWS::S3::Bucket
    Properties:
      VersioningConfiguration:
        Status: Enabled

Example: a minimal YAML template

Template

→

Change set
review first

→

Stack updated

Change sets prevent surprises: see what CloudFormation will add, modify, or delete before it happens.

AWS Elastic Beanstalk Revisited

AWS Elastic Beanstalk
application code → running environmentUpload code; get a load-balanced, auto-scaled environment quickly

AWS CloudFormation
underneathProvisions the actual infrastructure resources

CloudFormation: full control over every resource

Elastic Beanstalk: faster path, less control

Different levels of abstraction: Elastic Beanstalk trades some control for a faster path from code to a running environment.

AWS Systems Manager

Operations on already-running infrastructure:

Systems Manager Feature	What It Does
Run Command	Executes commands across a fleet of instances without SSH access
Patch Manager	Automates operating system and software patching
Parameter Store	Centralizes configuration values and secrets for applications to retrieve securely

CloudFormation

“How do I create this infrastructure?”

Systems Manager

“How do I operate and maintain it once it’s running?”

Key Terms

Infrastructure as code (IaC): Defining infrastructure in a version-controlled template rather than provisioning it manually
CloudFormation stack: A collection of AWS resources created and managed together from one template
Change set: A preview of what a CloudFormation stack update would change before it’s applied
AWS Systems Manager: A service for operational tasks — patching, running commands, managing configuration — on running infrastructure

Review Questions

What problem does infrastructure as code solve that manual console provisioning doesn’t?
What is a CloudFormation stack, and what does a change set let an architect verify before applying it?
How does AWS Elastic Beanstalk relate to AWS CloudFormation underneath?
What is the difference in purpose between AWS CloudFormation and AWS Systems Manager?