whitelist.sh

#!/usr/bin/env bash

# white list all public IPs from an AWS region in to a security group

security_group="sg-xxxxxx"
region="eu-west-1"
port="3306"

# list the public IPs from the instances in region
public_ips=`aws ec2 describe-instances --query "Reservations[*].Instances[*].PublicIpAddress" --output=text --region=${region} | xargs`

# Update the security group to allow the instance IPs on a given port number
for ip in ${public_ips}
do
    echo "White listing IP: ${ip}.."
    aws ec2 authorize-security-group-ingress --group-id ${security_group} --protocol tcp --port ${port} --cidr ${ip}/32
done