Fixing race condition when starting the GNS3 VM.

gns3server/controller/compute.py

@@ -377,13 +377,13 @@ class Compute:
         """
         :param dont_connect: If true do not reconnect if not connected
         """
+
         if not self._connected and not dont_connect:
             if self._id == "vm" and not self._controller.gns3vm.running:
                 yield from self._controller.gns3vm.start()
-
             yield from self.connect()
         if not self._connected and not dont_connect:
-            raise ComputeError("Can't connect to {}".format(self._name))
+            raise ComputeError("Cannot connect to compute '{}' with request {} {}".format(self._name, method, path))
         response = yield from self._run_http_query(method, path, data=data, **kwargs)
         return response
 
@@ -402,20 +402,20 @@ class Compute:
         """
         Check if remote server is accessible
         """
+
         if not self._connected and not self._closed:
             try:
+                log.info("Connecting to compute '{}'".format(self._id))
                 response = yield from self._run_http_query("GET", "/capabilities")
-            except ComputeError:
+            except ComputeError as e:
                 # Try to reconnect after 2 seconds if server unavailable only if not during tests (otherwise we create a ressources usage bomb)
                 if not hasattr(sys, "_called_from_test") or not sys._called_from_test:
                     self._connection_failure += 1
                     # After 5 failure we close the project using the compute to avoid sync issues
                     if self._connection_failure == 5:
-                        log.warning("Can't connect to compute %s", self._id)
+                        log.warning("Cannot connect to compute '{}': {}".format(self._id, e))
                         yield from self._controller.close_compute_projects(self)
-
                     asyncio.get_event_loop().call_later(2, lambda: asyncio.async(self._try_reconnect()))
-
                 return
             except aiohttp.web.HTTPNotFound:
                 raise aiohttp.web.HTTPConflict(text="The server {} is not a GNS3 server or it's a 1.X server".format(self._id))