add monitor socket

scripts/start

@@ -7,6 +7,7 @@ VM_MEMORY="${VM_MEMORY:-4G}"
 HOSTFWD="${HOSTFWD:-hostfwd=tcp::2222-:22}"
 DISK_IMG="${DISK_IMG:-./coreos_production_qemu_image.img}"
 CD_ARG=""
+MONITOR_OUTPUT="${MONITOR_OUTPUT:-unix:/tmp/kvm-mon}"
 
 if [ -n "${CLOUD_CONFIG_FILE}" ]; then
   echo "Setting cloud config file: ${CLOUD_CONFIG_FILE}"
@@ -51,4 +52,5 @@ qemu-system-x86_64 \
   -machine accel=kvm \
   -vga std \
   -smp 2 \
+  -monitor "${MONITOR_OUTPUT}" \
   $@