Infrastructure as Code

Infrastructure as Code (IaC)

Infrastructure as Code is the practice of managing and provisioning computing infrastructure through machine-readable configuration files, rather than through manual processes or interactive tools.

Manual vs IaC

  Manual Setup (Snowflake Servers):
  ┌──────────────────────────────┐
  │  SSH into server             │
  │  Install packages manually   │
  │  Copy config files           │
  │  "Works on my server!"       │
  │  - No version history       │
  │  - Not reproducible          │
  │  - Drift over time           │
  └──────────────────────────────┘

  Infrastructure as Code:
  ┌──────────────────────────────┐
  │  main.tf / playbook.yml      │
  │  ─────────────────────       │
  │  - Version controlled (Git)  │
  │  - Reproducible environments │
  │  - Consistent every time     │
  │  - Self-documenting          │
  │  - Automated provisioning    │
  └──────────────────────────────┘

IaC Tools

• Terraform — Multi-cloud, declarative, uses HCL language
• AWS CloudFormation — AWS-native, JSON/YAML templates
• Ansible — Agentless, uses YAML playbooks for configuration management
• Pulumi — Uses real programming languages (Python, TypeScript, Go)
• Chef/Puppet — Agent-based configuration management

Terraform Example

  # Create an AWS EC2 instance
  resource "aws_instance" "web" {
    ami           = "ami-0c55b159cbfafe1f0"
    instance_type = "t2.micro"

    tags = {
      Name = "WebServer"
      Environment = "production"
    }
  }

  # What this does:
  # 1. Declaratively describes desired state
  # 2. Terraform plans changes before applying
  # 3. Tracks state to detect drift
  # 4. Can destroy resources when no longer needed

IaC Benefits

• Reproducibility — Spin up identical environments in minutes
• Version control — Track infrastructure changes in Git
• Speed — Automate provisioning that took days manually
• Reliability — Eliminate human error from manual configuration
• Documentation — Code IS the documentation