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

exit 1

# Need the SystemAdministrator AWS SSO / IAM PermissionSet

for region in $(aws ec2 describe-regions --query 'Regions[].RegionName' --output text); do

    echo "* Region ${region}"

    # get default vpc
    vpc=$(aws ec2 --region ${region} describe-vpcs --filter Name=isDefault,Values=true --query 'Vpcs[0].VpcId' --output text)
    if [ "${vpc}" != "None" ]; then
        echo "Found default vpc ${vpc}"

        # get internet gateway
        igw=$(aws ec2 --region ${region} describe-internet-gateways --filter Name=attachment.vpc-id,Values=${vpc} --query 'InternetGateways[0].InternetGatewayId' --output text)
        if [ "${igw}" != "None" ]; then
            echo "Detaching and deleting internet gateway ${igw}"
            aws ec2 --region ${region} detach-internet-gateway --internet-gateway-id ${igw} --vpc-id ${vpc}
            aws ec2 --region ${region} delete-internet-gateway --internet-gateway-id ${igw}
        fi

        # get subnets
        subnets=$(aws ec2 --region ${region} describe-subnets --filters Name=vpc-id,Values=${vpc} --query 'Subnets[].SubnetId' --output text)
        if [ "${subnets}" != "None" ]; then
            for subnet in ${subnets}; do
                echo "Deleting subnet ${subnet}"
                aws ec2 --region ${region} delete-subnet --subnet-id ${subnet}
            done
        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 --region ${region} delete-vpc --vpc-id ${vpc}
    else
        echo "  No default vpc found"
    fi

    # # get dhcp options
    # dhcpoptions=$(aws ec2 --region ${region} describe-dhcp-options --query 'DhcpOptions[0].DhcpOptionsId' --output text)
    # if [ "${dhcpoptions}" != "None" ]; then
    #     for dhcp in ${dhcpoptions}; do

    #         if aws ec2 --region ${region} describe-dhcp-options --dhcp-options-id ${dhcp} --query 'DhcpOptions[0].DhcpConfigurations[].Key' --output text \
    #             | grep -q 'domain-name\s*domain-name-servers'; then
                
    #             if aws ec2 --region ${region} describe-dhcp-options --dhcp-options-id ${dhcp} --query 'DhcpOptions[0].DhcpConfigurations[].Values[].Value' --output text \
    #                 | grep -q -E '('$region'.compute.internal\s*AmazonProvidedDNS|ec2.internal\s*AmazonProvidedDNS)'; then

    #                 echo "Deleting dhcp-options ${dhcp}"
    #                 aws ec2 --region ${region} delete-dhcp-options --dhcp-options-id ${dhcp}

    #             fi
    #         fi
    #     done
    # fi

done