Shell script to restart all the salt minions on instances in the same VPC and AZ as this master running the script

restart_minions.sh

#!/bin/bash

eth0_mac=$(curl -s http://169.254.169.254/latest/meta-data/mac)
eth0_ip=$(curl -s http://169.254.169.254/latest/meta-data/local-ipv4/)

vpc_id=$(curl -s http://169.254.169.254/latest/meta-data/network/interfaces/macs/$eth0_mac/vpc-id)
az=$(curl -s http://169.254.169.254/latest/meta-data/placement/availability-zone/)
region=${az::-1}

instances=$(aws --region $region ec2 describe-instances --filters "Name=vpc-id,Values=$vpc_id" "Name=availability-zone,Values=$az" --query 'Reservations[*].Instances[*].PrivateIpAddress' --output=text)

for instance in $instances; do
    if [ $instance != "$eth0_ip" ]; then
        echo $instance
        # unfunk minions of an old master
        #ssh $instance "sudo rm -rf /etc/salt/pki/"

        # restart the minion
        ssh $instance "sudo service salt-minion restart"
    fi
done