Fix small errors like unhandled exceptions etc.

gns3server/compute/builtin/nodes/cloud.py

@@ -163,7 +163,7 @@ class Cloud(BaseNode):
 
         try:
             output = yield from gns3server.utils.asyncio.subprocess_check_output("networksetup", "-listallhardwareports")
-        except (FileNotFoundError, subprocess.SubprocessError) as e:
+        except (OSError, subprocess.SubprocessError) as e:
             log.warn("Could not execute networksetup: {}".format(e))
             return False
 

gns3server/compute/docker/docker_vm.py

@@ -526,8 +526,8 @@ class DockerVM(BaseNode):
         x11_socket = os.path.join("/tmp/.X11-unix/", "X{}".format(self._display))
         yield from wait_for_file_creation(x11_socket)
 
-        monitor_process(self._xvfb_process, self._xvfb_callback)
-        monitor_process(self._x11vnc_process, self._x11vnc_callback)
+        #monitor_process(self._xvfb_process, self._xvfb_callback)
+        #monitor_process(self._x11vnc_process, self._x11vnc_callback)
 
     def _xvfb_callback(self, returncode):
         """

gns3server/compute/iou/iou_vm.py

@@ -368,7 +368,7 @@ class IOUVM(BaseNode):
 
         try:
             output = yield from gns3server.utils.asyncio.subprocess_check_output("ldd", self._path)
-        except (FileNotFoundError, subprocess.SubprocessError) as e:
+        except (OSError, subprocess.SubprocessError) as e:
             log.warn("Could not determine the shared library dependencies for {}: {}".format(self._path, e))
             return
 
@@ -421,7 +421,7 @@ class IOUVM(BaseNode):
                 hostid = (yield from gns3server.utils.asyncio.subprocess_check_output("hostid")).strip()
             except FileNotFoundError as e:
                 raise IOUError("Could not find hostid: {}".format(e))
-            except subprocess.SubprocessError as e:
+            except (OSError, subprocess.SubprocessError) as e:
                 raise IOUError("Could not execute hostid: {}".format(e))
 
             try:

gns3server/compute/qemu/__init__.py

@@ -193,7 +193,7 @@ class Qemu(BaseManager):
                     return version
                 else:
                     raise QemuError("Could not determine the Qemu version for {}".format(qemu_path))
-            except subprocess.SubprocessError as e:
+            except (OSError, subprocess.SubprocessError) as e:
                 raise QemuError("Error while looking for the Qemu version: {}".format(e))
 
     @staticmethod
@@ -213,7 +213,7 @@ class Qemu(BaseManager):
                 return version
             else:
                 raise QemuError("Could not determine the Qemu-img version for {}".format(qemu_img_path))
-        except subprocess.SubprocessError as e:
+        except (OSError, subprocess.SubprocessError) as e:
             raise QemuError("Error while looking for the Qemu-img version: {}".format(e))
 
     @staticmethod

gns3server/compute/virtualbox/virtualbox_vm.py

@@ -217,6 +217,8 @@ class VirtualBoxVM(BaseNode):
             except ET.ParseError:
                 raise VirtualBoxError("Cannot modify VirtualBox linked nodes file. "
                                       "File {} is corrupted.".format(self._linked_vbox_file()))
+            except OSError as e:
+                raise VirtualBoxError("Cannot modify VirtualBox linked nodes file '{}': {}".format(self._linked_vbox_file(), e))
 
             machine = tree.getroot().find("{http://www.virtualbox.org/}Machine")
             if machine is not None and machine.get("uuid") != "{" + self.id + "}":
@@ -245,6 +247,7 @@ class VirtualBoxVM(BaseNode):
             return True
         return False
 
+    @locking
     @asyncio.coroutine
     def start(self):
         """