Find Unused Security Groups.sh

unused_security_groups.sh

#!/bin/bash

find_all_groups ()
{
    aws ec2 describe-security-groups \
        --query 'SecurityGroups[*].GroupId' \
        --output text \
    | tr '\t' '\n' \
    | sort -u
}

find_inuse_groups ()
{
    aws ec2 describe-network-interfaces \
        --query 'NetworkInterfaces[*].Groups[*].GroupId' \
        --output text \
    | tr '\t' '\n' \
    | sort -u
}

find_unused_groups ()
{
    comm -23 <(find_all_groups) <(find_inuse_groups)
}

aws ec2 describe-security-groups \
    --group-ids $(find_unused_groups) \
    --query 'SecurityGroups[*].{ID:GroupId,Name:GroupName,VPC:VpcId,Desc:Description}' \
    --output table