Fix crash when you start capture on a non running IOU

gns3server/handlers/api/iou_handler.py

@@ -16,7 +16,7 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 import os
-
+from aiohttp.web import HTTPConflict
 
 from ...web.route import Route
 from ...modules.port_manager import PortManager
@@ -255,7 +255,8 @@ class IOUHandler:
         status_codes={
             200: "Capture started",
             400: "Invalid request",
-            404: "Instance doesn't exist"
+            404: "Instance doesn't exist",
+            409: "VM not started"
         },
         description="Start a packet capture on a IOU VM instance",
         input=IOU_CAPTURE_SCHEMA)
@@ -266,8 +267,11 @@ class IOUHandler:
         adapter_number = int(request.match_info["adapter_number"])
         port_number = int(request.match_info["port_number"])
         pcap_file_path = os.path.join(vm.project.capture_working_directory(), request.json["capture_file_name"])
+
+        if not vm.is_running():
+            raise HTTPConflict(text="You can't capture the traffic on a non started VM")
         yield from vm.start_capture(adapter_number, port_number, pcap_file_path, request.json["data_link_type"])
-        response.json({"pcap_file_path": pcap_file_path})
+        response.json({"pcap_file_path": str(pcap_file_path)})
 
     @Route.post(
         r"/projects/{project_id}/iou/vms/{vm_id}/adapters/{adapter_number:\d+}/ports/{port_number:\d+}/stop_capture",
@@ -280,13 +284,18 @@ class IOUHandler:
         status_codes={
             204: "Capture stopped",
             400: "Invalid request",
-            404: "Instance doesn't exist"
+            404: "Instance doesn't exist",
+            409: "VM not started"
         },
         description="Stop a packet capture on a IOU VM instance")
     def stop_capture(request, response):
 
         iou_manager = IOU.instance()
         vm = iou_manager.get_vm(request.match_info["vm_id"], project_id=request.match_info["project_id"])
+
+        if not vm.is_running():
+            raise HTTPConflict(text="You can't capture the traffic on a non started VM")
+
         adapter_number = int(request.match_info["adapter_number"])
         port_number = int(request.match_info["port_number"])
         yield from vm.stop_capture(adapter_number, port_number)