test better shutdown nfstream

backend/src/utilities/nfstream_manager.py

@@ -185,6 +185,8 @@ class NFStreamManager:
             str(settings.nfstream_snapshot_length),
             "--n-dissections",
             str(settings.nfstream_n_dissections),
+            "--n-meters",
+            str(settings.nfstream_n_meters),
         ]
         if settings.nfstream_promiscuous_mode:
             cmd.append("--promiscuous-mode")
@@ -198,6 +200,7 @@ class NFStreamManager:
                 text=True,
                 bufsize=1,
                 env=env,
+                start_new_session=True,
             )
         except Exception:
             logger.exception("Failed to start NFStream worker for %s", iface)
@@ -226,10 +229,13 @@ class NFStreamManager:
 
         if process is not None and process.poll() is None:
             try:
-                process.send_signal(signal.SIGTERM)
+                os.killpg(os.getpgid(process.pid), signal.SIGTERM)
                 process.wait(timeout=settings.nfstream_process_stop_timeout_seconds)
             except subprocess.TimeoutExpired:
-                process.kill()
+                try:
+                    os.killpg(os.getpgid(process.pid), signal.SIGKILL)
+                except ProcessLookupError:
+                    pass
             except Exception:
                 logger.exception("Failed to stop NFStream worker for %s cleanly", iface)