feat: dynamically assign port and catalog URL in test setup

Author: Weijun-H

rerun_py/tests/unit/test_datafusion_tables.py

@@ -3,6 +3,7 @@
 import os
 import pathlib
 import platform
+import socket
 import subprocess
 import time
 from typing import TYPE_CHECKING
@@ -20,8 +21,9 @@
     from rerun_bindings import DatasetEntry
 
 HOST = "localhost"
-PORT = 51234
-CATALOG_URL = f"rerun+http://{HOST}:{PORT}"
+PORT = None  # Will be set dynamically
+CATALOG_URL = None  # Will be set dynamically
+# CATALOG_URL = f"rerun+http://{HOST}:{PORT}"
 DATASET_NAME = "dataset"
 
 DATASET_FILEPATH = pathlib.Path(__file__).parent.parent.parent.parent / "tests" / "assets" / "rrd" / "dataset"
@@ -85,8 +87,6 @@ def shutdown_process(process: subprocess.Popen[str]) -> None:
 
 
 def wait_for_server_ready(timeout: int = 30) -> None:
-    import socket
-
     def is_port_open() -> bool:
         sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
         sock.settimeout(1)
@@ -123,7 +123,16 @@ def server_instance() -> Generator[ServerInstance, None, None]:
         # Server can be noisy by default
         env["RUST_LOG"] = "warning"
 
-    # TODO(#11173): pick a free port
+    # Find a free port dynamically
+    with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
+        s.bind((HOST, 0))
+        free_port = s.getsockname()[1]
+
+    # Set the global variables for the session
+    global PORT, CATALOG_URL
+    PORT = free_port
+    CATALOG_URL = f"rerun+http://{HOST}:{PORT}"
+
     cmd = ["python", "-m", "rerun", "server", "--dataset", str(DATASET_FILEPATH), "--table", str(TABLE_FILEPATH)]
     server_process = subprocess.Popen(cmd, env=env, stdout=subprocess.PIPE, stderr=subprocess.PIPE, text=True)