Docker: Simplify port-bound check

bblommers · bblommers · commit 34e7415a4718 · 2025-04-03T12:00:50.000Z
diff --git a/localstack-core/localstack/utils/docker_utils.py b/localstack-core/localstack/utils/docker_utils.py
@@ -5,15 +5,14 @@
 from typing import List, Optional, Union
 
 from localstack import config
-from localstack.constants import DEFAULT_VOLUME_DIR, DOCKER_IMAGE_NAME
+from localstack.constants import DEFAULT_VOLUME_DIR
 from localstack.utils.collections import ensure_list
 from localstack.utils.container_utils.container_client import (
     ContainerClient,
     PortMappings,
     VolumeInfo,
 )
 from localstack.utils.net import IntOrPort, Port, PortNotAvailableException, PortRange
-from localstack.utils.objects import singleton_factory
 from localstack.utils.strings import to_str
 
 LOG = logging.getLogger(__name__)
@@ -147,23 +146,22 @@ def container_ports_can_be_bound(
         port_mappings.add(port.port, port.port, protocol=port.protocol)
     try:
         result = DOCKER_CLIENT.run_container(
-            _get_ports_check_docker_image(),
-            entrypoint="sh",
-            command=["-c", "echo test123"],
+            "bash",
+            command=["echo", "test123"],
             ports=port_mappings,
             remove=True,
         )
     except Exception as e:
-        if "port is already allocated" not in str(e) and "address already in use" not in str(e):
+        if "address already in use" not in str(e):
             LOG.warning(
-                "Unexpected error when attempting to determine container port status: %s", e
+                "Unexpected error when attempting to determine container port status", exc_info=e
             )
         return False
     # TODO(srw): sometimes the command output from the docker container is "None", particularly when this function is
     #  invoked multiple times consecutively. Work out why.
     if to_str(result[0] or "").strip() != "test123":
         LOG.warning(
-            "Unexpected output when attempting to determine container port status: %s", result[0]
+            "Unexpected output when attempting to determine container port status: %s", result
         )
     return True
 
@@ -240,29 +238,4 @@ def _random_port():
     )
 
 
-@singleton_factory
-def _get_ports_check_docker_image() -> str:
-    """
-    Determine the Docker image to use for Docker port availability checks.
-    Uses either PORTS_CHECK_DOCKER_IMAGE (if configured), or otherwise inspects the running container's image.
-    """
-    if config.PORTS_CHECK_DOCKER_IMAGE:
-        # explicit configuration takes precedence
-        return config.PORTS_CHECK_DOCKER_IMAGE
-    if not config.is_in_docker:
-        # local import to prevent circular imports
-        from localstack.utils.bootstrap import get_docker_image_to_start
-
-        # Use whatever image the user is trying to run LocalStack with, since they either have
-        # it already, or need it by definition to start LocalStack.
-        return get_docker_image_to_start()
-    try:
-        # inspect the running container to determine the image
-        container = DOCKER_CLIENT.inspect_container(get_current_container_id())
-        return container["Config"]["Image"]
-    except Exception:
-        # fall back to using the default Docker image
-        return DOCKER_IMAGE_NAME
-
-
 DOCKER_CLIENT: ContainerClient = create_docker_client()
diff --git a/tests/integration/docker_utils/test_docker.py b/tests/integration/docker_utils/test_docker.py
@@ -14,7 +14,6 @@
 from localstack import config
 from localstack.config import in_docker
 from localstack.testing.pytest import markers
-from localstack.utils import docker_utils
 from localstack.utils.common import is_ipv4_address, save_file, short_uid, to_str
 from localstack.utils.container_utils.container_client import (
     AccessDenied,
@@ -1894,18 +1893,6 @@ def test_container_with_sec_opt(self, docker_client: ContainerClient, create_con
         assert security_opt == inspect_result["HostConfig"]["SecurityOpt"]
 
 
-@pytest.fixture
-def set_ports_check_image_alpine(monkeypatch):
-    """Set the ports check Docker image to 'alpine', to avoid pulling the larger localstack image in the tests"""
-
-    def _get_ports_check_docker_image():
-        return "alpine"
-
-    monkeypatch.setattr(
-        docker_utils, "_get_ports_check_docker_image", _get_ports_check_docker_image
-    )
-
-
 @pytest.mark.parametrize("protocol", [None, "tcp", "udp"])
 class TestDockerPorts:
     def test_reserve_container_port(self, docker_client, set_ports_check_image_alpine, protocol):
