Format AWS VPC Terraform Configuration

Formatting AWS VPC Resources

A VPC configuration is one of the most common Terraform patterns, typically involving multiple interconnected resources. Proper formatting makes the network topology visible in the code itself.

Example VPC Configuration

resource "aws_vpc" "main" {
  cidr_block           = "10.0.0.0/16"
  enable_dns_support   = true
  enable_dns_hostnames = true
  instance_tenancy     = "default"

  tags = {
    Name        = "main-vpc"
    Environment = "production"
    ManagedBy   = "terraform"
  }
}

resource "aws_internet_gateway" "main" {
  vpc_id = aws_vpc.main.id

  tags = {
    Name = "main-igw"
  }
}

resource "aws_subnet" "public" {
  count = 3

  vpc_id                  = aws_vpc.main.id
  cidr_block              = cidrsubnet(aws_vpc.main.cidr_block, 8, count.index)
  availability_zone       = data.aws_availability_zones.available.names[count.index]
  map_public_ip_on_launch = true

  tags = {
    Name = "public-subnet-${count.index}"
    Type = "public"
  }
}

Formatting Highlights

• Tag blocks aligned: Within each tags block, keys and values line up vertically
• Boolean alignment: enable_dns_support and enable_dns_hostnames have their = and true values aligned
• Resource separation: Blank lines between resources and between attribute groups within resources
• Count meta-argument: Placed at the top of the resource block, separated from regular attributes

Network Topology Readability

When your VPC configuration includes 10+ resources (VPC, subnets, route tables, NAT gateways, security groups), consistent formatting lets you scan the file and understand the topology without reading every line.