DEVX-21: fix: always start dockerd in CI runner for molecule tests

.taskid

@@ -1 +1 @@
-DEVX-20
+DEVX-21

src/devx/molecule/start_docker.py

@@ -1,10 +1,10 @@
 #!/usr/bin/env python3
 """Start a Docker daemon inside a CI runner container (Docker-in-Docker).
 
-CI runners (e.g. ``gitea/runner-images:ubuntu-latest``) may not have a
+CI runners (e.g. ``gitea/runner-images:ubuntu-latest``) may have the host's
-Docker daemon running. This module starts ``dockerd`` in the background
+Docker socket mounted, but molecule needs a local Docker daemon to create
-and waits for it to become ready, or exits immediately if Docker is
+nested containers. This module always starts ``dockerd`` in the background
-already available.
+and waits for it to become ready.
 
 Usage::
 
@@ -38,14 +38,13 @@ def is_docker_ready() -> bool:
 def start_docker_daemon(timeout: int = DEFAULT_TIMEOUT) -> bool:
     """Start dockerd in the background and wait for it to be ready.
 
-    Returns ``True`` if Docker is ready (either already running or
+    Always starts a local dockerd even if ``docker info`` succeeds,
-    successfully started), ``False`` if it failed to start within
+    because the host socket may be mounted but not suitable for
-    the timeout.
+    molecule's nested container creation.
-    """
-    if is_docker_ready():
-        click.echo(_("Docker daemon already running"))
-        return True
 
+    Returns ``True`` if Docker is ready, ``False`` if it failed to
+    start within the timeout.
+    """
     click.echo(_("Starting Docker daemon..."))
     log_file = open(DOCKERD_LOG, "w")  # noqa: SIM115
     subprocess.Popen(  # nosec B603 B607

src/devx/translations.json

@@ -419,13 +419,6 @@
     "ru": "Created release commit.",
     "zh": "Created release commit."
   },
-  "Docker daemon already running": {
-    "bg": "Docker daemon already running",
-    "de": "Docker-Daemon läuft bereits",
-    "en": "Docker daemon already running",
-    "ru": "Docker-демон уже запущен",
-    "zh": "Docker 守护进程已在运行"
-  },
   "Docker daemon failed to start": {
     "bg": "Docker daemon failed to start",
     "de": "Docker-Daemon konnte nicht gestartet werden",

tests/unit/test_start_docker.py

@@ -21,11 +21,6 @@ class TestIsDockerReady:
 
 
 class TestStartDockerDaemon:
-    @patch("devx.molecule.start_docker.is_docker_ready", return_value=True)
-    def test_already_running(self, mock_ready: MagicMock) -> None:
-        assert start_docker_daemon() is True
-        mock_ready.assert_called_once()
-
     @patch("devx.molecule.start_docker.time.sleep")
     @patch("devx.molecule.start_docker.is_docker_ready")
     @patch("devx.molecule.start_docker.subprocess.Popen")
@@ -37,11 +32,11 @@ class TestStartDockerDaemon:
         mock_ready: MagicMock,
         mock_sleep: MagicMock,
     ) -> None:
-        # First call: initial check (not ready). Second: first loop iteration (ready).
+        # First loop iteration: dockerd not ready yet. Second: ready.
         mock_ready.side_effect = [False, True]
         assert start_docker_daemon(timeout=5) is True
         mock_popen.assert_called_once()
-        mock_sleep.assert_not_called()
+        mock_sleep.assert_called_once_with(1)
 
     @patch("devx.molecule.start_docker.time.sleep")
     @patch("devx.molecule.start_docker.is_docker_ready", return_value=False)
@@ -54,11 +49,26 @@ class TestStartDockerDaemon:
         mock_ready: MagicMock,
         mock_sleep: MagicMock,
     ) -> None:
-        # is_docker_ready always returns False: 1 initial + 3 loop iterations = 4 calls
         assert start_docker_daemon(timeout=3) is False
         mock_popen.assert_called_once()
         assert mock_sleep.call_count == 3
 
+    @patch("devx.molecule.start_docker.time.sleep")
+    @patch("devx.molecule.start_docker.is_docker_ready")
+    @patch("devx.molecule.start_docker.subprocess.Popen")
+    @patch("builtins.open", new_callable=mock_open)
+    def test_ready_on_first_check(
+        self,
+        mock_file: MagicMock,
+        mock_popen: MagicMock,
+        mock_ready: MagicMock,
+        mock_sleep: MagicMock,
+    ) -> None:
+        mock_ready.return_value = True
+        assert start_docker_daemon(timeout=5) is True
+        mock_popen.assert_called_once()
+        mock_sleep.assert_not_called()
+
     @patch("devx.molecule.start_docker.time.sleep")
     @patch("devx.molecule.start_docker.is_docker_ready")
     @patch("devx.molecule.start_docker.subprocess.Popen")
@@ -70,9 +80,8 @@ class TestStartDockerDaemon:
         mock_ready: MagicMock,
         mock_sleep: MagicMock,
     ) -> None:
-        # First call: initial check (not ready). Then 9 loop iterations (not ready),
+        # 9 iterations not ready, 10th ready.
-        # 10th iteration (ready).
+        mock_ready.side_effect = [False] * 9 + [True]
-        mock_ready.side_effect = [False] * 10 + [True]
         assert start_docker_daemon(timeout=10) is True
         assert mock_sleep.call_count == 9