Untitled

#!/bin/bash

SUBNET_ID=subnet-12345678

# Get the subnet CIDR
CIDR_BLOCK=$(aws ec2 describe-subnets --subnet-ids $SUBNET_ID --query "Subnets[0].CidrBlock" --output text)

# Calculate the total number of IPs in the CIDR block
TOTAL_IPS=$(ipcalc -n $CIDR_BLOCK | grep Hosts | awk '{print $2}')

# Get the network interfaces (ENIs) in the subnet
ENIS=$(aws ec2 describe-network-interfaces --filters "Name=subnet-id,Values=$SUBNET_ID" --query "NetworkInterfaces[*].[NetworkInterfaceId,PrivateIpAddresses[*].PrivateIpAddress]" --output json)

# Initialize counters
USED_IPS=0

echo "Used IPs and their associated resources in subnet $SUBNET_ID:"

# Loop through each ENI to get information about the associated resource
echo "$ENIS" | jq -c '.[]' | while read eni; do
  ENI_ID=$(echo $eni | jq -r '.[0]')
  IP_ADDRESSES=$(echo $eni | jq -r '.[1][]')
  ((USED_IPS+= $(echo "$IP_ADDRESSES" | wc -l)))

  # Get the description and associated resource for the ENI
  RESOURCE_INFO=$(aws ec2 describe-network-interfaces --network-interface-ids $ENI_ID --query "NetworkInterfaces[0].Attachment.InstanceId,NetworkInterfaces[0].Description" --output text)
  
  echo "ENI: $ENI_ID"
  echo "IP Addresses: $IP_ADDRESSES"
  echo "Associated Resource: $RESOURCE_INFO"
  echo "-----------------------------------"
done

# Calculate the available IPs
AVAILABLE_IPS=$(($TOTAL_IPS - $USED_IPS))

echo "Total IPs: $TOTAL_IPS"
echo "Used IPs: $USED_IPS"
echo "Available IPs: $AVAILABLE_IPS"