#!/bin/bash

command=$* #Command to run. Example: aws.sh echo "Hello World!"
exit=0

for ID in $(aws autoscaling describe-auto-scaling-instances --region us-east-1 --query AutoScalingInstances[].InstanceId --output text);  do
    for IP in $(aws ec2 describe-instances --instance-ids $ID --region us-east-1 --query Reservations[].Instances[].PrivateIpAddress --output text|awk '{print $4}'); do
        ssh $IP $command  2>&1 >/tmp/out$i  &
        pids[${i}]=$!.
done

for pid in ${!pids[@]}; do
    wait ${pids[$pid]} || { echo Server $pid failed. Output: ; cat /tmp/out$pid ; }
done