Script to delete all AWS default VPCs from all regions using AWS CLI

aws_delete-default-vpc.sh

#!/usr/bin/env bash

set -euo pipefail

for AWS_REGION in $(aws ec2 describe-regions --region eu-west-1 --query '[Regions[].RegionName]' --output text); do
  echo -n "* Region ${AWS_REGION}: "
  export AWS_REGION

  # get default vpc
  vpc=$(aws ec2 describe-vpcs --filter Name=isDefault,Values=true --query "Vpcs[0].VpcId" --output text)
  if [[ "${vpc}" = "None" ]]; then
    echo "no default VPC found"
    continue
  fi
  echo "default VPC ${vpc}"

  # get internet gateway
  igw=$(aws ec2 describe-internet-gateways --filter Name=attachment.vpc-id,Values=${vpc} --query "InternetGateways[0].InternetGatewayId" --output text)
  if [[ "${igw}" != "None" ]]; then
    echo "  - Detaching and deleting internet gateway ${igw}"
    aws ec2 detach-internet-gateway --internet-gateway-id ${igw} --vpc-id ${vpc}
    aws ec2 delete-internet-gateway --internet-gateway-id ${igw}
  else
    echo "  - No internet gateway found"
  fi

  # get subnets
  subnets=$(aws ec2 describe-subnets --filters Name=vpc-id,Values=${vpc} --query '[Subnets[].SubnetId]' --output text)
  if [[ -n "${subnets}" ]]; then
    echo "  - Subnets: ${subnets}"
    for subnet in ${subnets}; do
      echo "    + Deleting subnet ${subnet}"
      aws ec2 delete-subnet --subnet-id ${subnet}
    done
  else
    echo "  - Subnets: none found"
  fi

  # https://docs.aws.amazon.com/cli/latest/reference/ec2/delete-vpc.html
  # - You can't delete the main route table
  # - You can't delete the default network acl
  # - You can't delete the default security group

  # delete default vpc
  echo "  - Deleting VPC ${vpc}"
  aws ec2 delete-vpc --vpc-id ${vpc}
done