Terraform Infrastructure as Code

2025-01-13

NAME

terraform - define infrastructure using declarative configuration

SYNOPSIS

resource "aws_s3_bucket" "blog" {
  bucket = "vgnshlvnz-blog"

  tags = {
    Name = "ManpageBlog"
    Cost = "Minimal"
  }
}

DESCRIPTION

Terraform is the industry standard for Infrastructure as Code (IaC). It allows you to define cloud resources using a declarative configuration language (HCL), making infrastructure reproducible, versionable, and testable.

This platform uses Terraform to define all AWS resources, ensuring consistent deployments across environments.

CONFIGURATION

S3 Bucket

The blog content is stored in S3 with versioning enabled:

resource "aws_s3_bucket" "blog" {
  bucket = "vgnshlvnz-blog"
}

resource "aws_s3_bucket_versioning" "blog" {
  bucket = aws_s3_bucket.blog.id

  versioning_configuration {
    status = "Enabled"
  }
}

resource "aws_s3_bucket_lifecycle_configuration" "blog" {
  bucket = aws_s3_bucket.blog.id

  rule {
    id     = "archive-old-content"
    status = "Enabled"

    transition {
      days          = 90
      storage_class = "STANDARD_IA"
    }

    transition {
      days          = 180
      storage_class = "GLACIER_IR"
    }
  }
}

CloudFront Distribution

CDN configuration with aggressive caching:

resource "aws_cloudfront_distribution" "blog" {
  origin {
    domain_name = aws_s3_bucket.blog.bucket_regional_domain_name
    origin_id   = "S3-${aws_s3_bucket.blog.id}"
  }

  enabled             = true
  is_ipv6_enabled     = true
  default_root_object = "index.html"
  price_class         = "PriceClass_100"

  default_cache_behavior {
    allowed_methods  = ["GET", "HEAD", "OPTIONS"]
    cached_methods   = ["GET", "HEAD"]
    target_origin_id = "S3-${aws_s3_bucket.blog.id}"

    forwarded_values {
      query_string = false
      cookies {
        forward = "none"
      }
    }

    viewer_protocol_policy = "redirect-to-https"
    min_ttl                = 86400    # 1 day
    default_ttl            = 604800   # 7 days
    max_ttl                = 31536000 # 1 year
    compress               = true
  }
}

Budget Alerts

Cost monitoring with alerts:

resource "aws_budgets_budget" "monthly" {
  name         = "manpageblog-monthly"
  budget_type  = "COST"
  limit_amount = "10.0"
  limit_unit   = "USD"
  time_unit    = "MONTHLY"

  notification {
    comparison_operator        = "GREATER_THAN"
    threshold                  = 80
    threshold_type             = "PERCENTAGE"
    notification_type          = "ACTUAL"
    subscriber_email_addresses = ["admin@vgnshlv.nz"]
  }
}

DEPLOYMENT WORKFLOW

The infrastructure deployment follows this workflow:

# Initialize Terraform
terraform init

# Plan changes
terraform plan -out=tfplan

# Apply changes
terraform apply tfplan

# Verify deployment
terraform show

STATE MANAGEMENT

Terraform state is stored remotely in S3 with DynamoDB locking:

terraform {
  backend "s3" {
    bucket         = "vgnshlvnz-terraform-state"
    key            = "blog/terraform.tfstate"
    region         = "us-east-1"
    dynamodb_table = "terraform-locks"
    encrypt        = true
  }
}

COST ESTIMATION

Terraform can estimate costs before deployment:

# Using Infracost
infracost breakdown --path .

# Output:
# ┌─────────────────────────────────────────────┐
# │ Monthly cost estimate                        │
# ├─────────────────────────────────────────────┤
# │ S3 Storage (5GB)            $0.12           │
# │ CloudFront (10k requests)   $0.85           │
# │ Route53 (hosted zone)       $0.50           │
# │ Lambda (within free tier)   $0.00           │
# ├─────────────────────────────────────────────┤
# │ TOTAL                       $1.47/month     │
# └─────────────────────────────────────────────┘

BENEFITS

Using Terraform provides:

Reproducibility - Same config, same infrastructure every time
Version Control - Infrastructure changes tracked in Git
Documentation - Code serves as living documentation
Testing - Infrastructure can be tested before deployment
Cost Tracking - Estimate costs before applying changes

EXAMPLE PROJECT STRUCTURE

terraform/
├── main.tf           # Primary resources
├── variables.tf      # Input variables
├── outputs.tf        # Output values
├── versions.tf       # Provider versions
├── backend.tf        # State configuration
└── modules/
    ├── s3/
    ├── cloudfront/
    └── lambda/

AUTHOR

vgnshlvnz - Building infrastructure with code since 2025

NAME