Make service alive checking more universal

python/arcticdb/storage_fixtures/utils.py

@@ -92,7 +92,10 @@ def terminate(p: Union[multiprocessing.Process, subprocess.Popen]):
 
 def wait_for_server_to_come_up(url: str, service: str, process: ProcessUnion, *, timeout=20, sleep=0.2, req_timeout=1):
  deadline = time.time() + timeout
- alive = (lambda: process.poll() is None) if isinstance(process, subprocess.Popen) else process.is_alive
+ if process is None:
+ alive = lambda: True
+ else:
+ alive = (lambda: process.poll() is None) if isinstance(process, subprocess.Popen) else process.is_alive
  while True:
  assert time.time() < deadline, f"Timed out waiting for {service} process to start"
  assert alive(), service + " process died shortly after start up"