block_ip

#!/bin/bash
aclid=acl-d347edbc
start_rule=1000
cidr=$1

if [ -z "${cidr}" ] ; then
    echo "Must provide CIDR block to DENY"
    exit 1
fi

used_entries=$(aws ec2 describe-network-acls --network-acl-ids ${aclid} \
               --output text | grep ENTRIES | grep False | awk '{print $6}')


rule=$start_rule
while grep $rule <(echo "${used_entries}") > /dev/null ; do
    ((rule+=1))
done

echo "Adding new rule: ${rule} DENY ingress from ${cidr}"

aws ec2 create-network-acl-entry --network-acl-id "${aclid}" \
                                 --cidr-block "${cidr}" \
                                 --rule-number ${rule} \
                                 --rule-action deny \
                                 --ingress \
                                 --protocol all