function oc-ips {
    aws_profile=${1:-test}
    cluster_name=$(sed -n 's/cluster=cluster_config-\([^\.]\+\)\.json/\1/p' .ocopsworks.rc)
    aws --profile $aws_profile ec2 describe-instances \
        --output text \
        --filters "Name=tag:opsworks:stack,Values=$cluster_name" \
        --query "Reservations[].Instances[].[Tags[?Key=='opsworks:instance']|[0].Value,PublicIpAddress]" \
        > .oc-ips
}

function ssh_to {
    hostname=$1
    ip=$(grep "^$hostname" .oc-ips | cut -f 2)
    ssh -A -t $ip
}