Fix connection-refused race condition when spawning tasks

Signed-off-by: Plamen Dimitrov <[email protected]>

Author: pevogam

avocado/core/nrunner/task.py

@@ -2,6 +2,7 @@
 import json
 import socket
 import tempfile
+import time
 from uuid import uuid1
 
 from avocado.core.nrunner.runnable import (
@@ -41,7 +42,16 @@ def post(self, status):
             host, port = self.uri.split(':')
             port = int(port)
             if self.connection is None:
-                self.connection = socket.create_connection((host, port))
+                for _ in range(30):
+                    try:
+                        self.connection = socket.create_connection((host, port))
+                        break
+                    except ConnectionRefusedError as error:
+                        # TODO: should we at least provide some logging here?
+                        #logging.error(error)
+                        time.sleep(1)
+                else:
+                    raise error
         else:
             if self.connection is None:
                 self.connection = socket.socket(socket.AF_UNIX,