Infrastructure as Code

What is Infrastructure Automation?

Infrastructure automation is creating and managing infrastructure with code instead of clicking through a cloud console.

Traditional approach

Human
  ↓
AWS Console
  ↓
Create Infrastructure

Automated approach

Code
  ↓
Automation Tool
  ↓
Create Infrastructure

Example

Instead of manually launching an EC2 instance, you write:

resource "aws_instance" "web" {
  ami           = "ami-0df7a207adb9748c7"
  instance_type = "t2.micro"
}

Then run the automation tool — and the instance is created for you.

Benefits of Infrastructure Automation

What is Infrastructure as Code (IaC)?

Infrastructure as Code means you define infrastructure in files — the same way you define application code.

Those files can be:

• Stored in Git
• Reviewed in pull requests
• Reused across environments
• Applied automatically in CI/CD

Benefits

• Repeatable environments
• Auditable changes
• Faster onboarding
• Disaster recovery from code

Popular IaC tools

Procedural vs Declarative

Procedural (imperative)

You tell the tool how to do each step:

1. Create VPC
2. Create Subnet
3. Create Security Group
4. Launch EC2

Example with the AWS CLI:

aws ec2 run-instances \
  --image-id ami-0df7a207adb9748c7 \
  --instance-type t2.micro

You own the sequence. If a step fails mid-way, you must handle cleanup and retries yourself.

Declarative

You describe the desired end state. The tool figures out how to get there:

resource "aws_instance" "web" {
  ami           = "ami-0df7a207adb9748c7"
  instance_type = "t2.micro"
}

Terraform compares current state to desired state and creates, updates, or destroys resources as needed.

Comparison