Attach a volume to an instance and try to detect which device it ended up on. Hacky.

gistfile1.txt

attach_volume () {
        volId=$1

        grep vd[a-z]$ /proc/partitions | awk "{print \$4;}" > /tmp/before
        sleep 2

        # attach the volume
        echo "Attaching $volId to $instanceId"
        euca-attach-volume -i $instanceId $volId -d /dev/vdc

        sleep 5

        # detect which device the volume is attached to
        grep vd[a-z]$ /proc/partitions | awk "{print \$4;}" > /tmp/after
        NEWDEV=$(diff -C0 /tmp/before /tmp/after | grep ^+ | awk "{print \$2;}")

        if [ ! $NEWDEV ]; then
                echo "Can't detect newly-attached device--quitting."
                exit 1
        fi

        rm -f /tmp/before /tmp/after
}