list_aws_vpcs

#!/bin/bash
#
# This script is used to list all VPCs in the AWS account.
################################################################################
#
usage () {
  cat 1>&2 <<EOF
Usage: $(basename $0) [-a] [-r region] [-s]
where: -a list - All regions
       -r region - List VPCs in the specified region
       -s - List all the subnets in the VPC
       -q - Supress extraineous output
       -h - Print this help message
EOF
  exit 1
}

# Check if the required tools are installed
for tool in aws jq; do
  if which $tool > /dev/null 2>&1; then
    :
  else
    echo "Error, $tool command is rquired to run this script."
    exit 1
  fi
done

allRegions=False
regions=""
subnets=False
quiet=False
while getopts "qsar:h" opt; do
  case $opt in
    a) allRegions=True
      ;;
    r) regions=$OPTARG
      ;;
    s) subnets=True
      ;;
    q) quiet=True
      ;;
    *) usage
      ;;
  esac
done

tmpout=/tmp/list_aws_vpcs.$$
trap 'rm -f $tmpout' exit

if [ "$allRegions" == "True" ]; then
  regions=$(aws ec2 describe-regions --query "Regions[].RegionName" --output=text)
else
  if [ -z "$regions" ]; then
     regions=$(aws configure get region)
  fi
fi

vpcFormatStr="%21s  %19s  %s\n"
for region in $regions; do
  [ "$quiet" != "True" ] && printf "\nRegion: $region\n"
  first=True
  aws ec2 describe-vpcs --region=$region | jq -r '.Vpcs[] | .VpcId + " " + .CidrBlock + " " + (if (has("Tags")) then .Tags[] | (select(.Key == "Name") .Value) else "" end)' |  \
    while read vpcId cidr name; do
      if [ "$quiet" != "True" -a "$first" == "True" ]; then
        printf "\n$vpcFormatStr" "VPC IP" "CIDR" "Name"
        first=False
      fi
      echo "$vpcId,$cidr,$name" | awk -F, '{printf "'"$vpcFormatStr"'", $1, $2, $3}'
      
      if [ "$subnets" == "True" ]; then
        printf "\n\tSubnets:\n"
        aws ec2 describe-subnets --region=$region --filters '[{"Name": "vpc-id", "Values": ["'$vpcId'"]}]' | jq -r '.Subnets[] | .VpcId + " " + .SubnetId + " " + .CidrBlock + " " + (if(has("Tags")) then first(.Tags[] | select(.Key == "Name").Value) // "" else "" end)' | awk 'BEGIN {formatStr="\t\t%24s  %18s  %s\n"; printf(formatStr, "Subnet ID", "CIDR", "Name")} {name=$4; for (i=5; i<=NF; i++) {name=name " " $(i)}; printf(formatStr , $2, $3, name)}'
        first=True
      fi
  done
done