DEVX-29: fix: use DOCKER_HOST env var in is_docker_ready + scan all rootless sockets

.taskid

@@ -1 +1 @@
-DEVX-28
+DEVX-29

src/devx/molecule/start_docker.py

@@ -17,6 +17,7 @@ Usage::
 
 from __future__ import annotations
 
+import glob
 import os
 import subprocess  # nosec B404
 import sys
@@ -35,11 +36,12 @@ ROOTLESS_SOCK = f"/run/user/{os.getuid()}/docker.sock"
 
 def is_docker_ready() -> bool:
     """Check if Docker daemon is responding on the configured socket."""
+    docker_host = os.environ.get("DOCKER_HOST", f"unix://{DOCKER_SOCK}")
     result = subprocess.run(  # nosec B603 B607
         ["docker", "info"],
         capture_output=True,
         check=False,
-        env={**os.environ, "DOCKER_HOST": f"unix://{DOCKER_SOCK}"},
+        env={**os.environ, "DOCKER_HOST": docker_host},
     )
     return result.returncode == 0
 
@@ -123,8 +125,21 @@ def start_docker_daemon(timeout: int = DEFAULT_TIMEOUT) -> bool:
         click.echo(_("Docker daemon already running"))
         return True
 
+    # Scan for any rootless sockets at other UIDs
+    for sock in sorted(glob.glob("/run/user/*/docker.sock")):
+        if sock == ROOTLESS_SOCK:
+            continue
+        click.echo(f"Trying alternative rootless socket: {sock}")
+        os.environ["DOCKER_HOST"] = f"unix://{sock}"
+        if is_docker_ready():
+            click.echo(_("Docker daemon already running"))
+            return True
+
     click.echo(_("Host Docker not available, starting local dockerd..."))
 
+    # Reset DOCKER_HOST to host socket for local dockerd
+    os.environ["DOCKER_HOST"] = f"unix://{DOCKER_SOCK}"
+
     # Start local dockerd (requires privileged container)
     log_file = tempfile.NamedTemporaryFile(  # noqa: SIM115
         mode="w", suffix="dockerd.log", delete=False

tests/unit/test_start_docker.py

@@ -1,5 +1,6 @@
 """Unit tests for devx.molecule.start_docker."""
 
+import os
 from unittest.mock import MagicMock, mock_open, patch
 
 from click.testing import CliRunner
@@ -17,7 +18,8 @@ class TestIsDockerReady:
     @patch("devx.molecule.start_docker.subprocess.run")
     def test_ready(self, mock_run: MagicMock) -> None:
         mock_run.return_value = MagicMock(returncode=0)
-        assert is_docker_ready() is True
+        with patch.dict("os.environ", {"DOCKER_HOST": f"unix://{DOCKER_SOCK}"}, clear=False):
+            assert is_docker_ready() is True
         call_kwargs = mock_run.call_args
         assert call_kwargs.args[0] == ["docker", "info"]
         assert call_kwargs.kwargs["env"]["DOCKER_HOST"] == f"unix://{DOCKER_SOCK}"
@@ -27,6 +29,16 @@ class TestIsDockerReady:
         mock_run.return_value = MagicMock(returncode=1)
         assert is_docker_ready() is False
 
+    @patch("devx.molecule.start_docker.subprocess.run")
+    def test_uses_docker_host_env(self, mock_run: MagicMock) -> None:
+        """Should check the socket specified by DOCKER_HOST env var."""
+        mock_run.return_value = MagicMock(returncode=0)
+        rootless = "unix:///run/user/999/docker.sock"
+        with patch.dict("os.environ", {"DOCKER_HOST": rootless}, clear=False):
+            assert is_docker_ready() is True
+        call_kwargs = mock_run.call_args
+        assert call_kwargs.kwargs["env"]["DOCKER_HOST"] == rootless
+
 
 class TestDiagnoseSocket:
     @patch("devx.molecule.start_docker.os.stat")
@@ -76,8 +88,44 @@ class TestStartDockerDaemon:
         """Should use rootless socket if host socket fails."""
         # First check (host) fails, second check (rootless) succeeds
         mock_ready.side_effect = [False, True]
-        assert start_docker_daemon(timeout=5) is True
+        with patch("devx.molecule.start_docker.glob.glob", return_value=[]):
+            assert start_docker_daemon(timeout=5) is True
 
+    @patch("devx.molecule.start_docker._diagnose_socket")
+    @patch("devx.molecule.start_docker.os.path.exists", return_value=True)
+    @patch("devx.molecule.start_docker.is_docker_ready")
+    def test_alt_rootless_socket_found(
+        self, mock_ready: MagicMock, mock_exists: MagicMock, mock_diag: MagicMock
+    ) -> None:
+        """Should find rootless socket at a different UID via glob scan."""
+        # Host fails, own rootless fails, alt rootless succeeds
+        mock_ready.side_effect = [False, False, True]
+        alt_sock = "/run/user/999/docker.sock"
+        with patch("devx.molecule.start_docker.glob.glob", return_value=[alt_sock]):
+            assert start_docker_daemon(timeout=5) is True
+
+    @patch("devx.molecule.start_docker._diagnose_socket")
+    @patch("devx.molecule.start_docker.os.path.exists", return_value=True)
+    @patch("devx.molecule.start_docker.is_docker_ready")
+    def test_alt_rootless_socket_skips_own(
+        self, mock_ready: MagicMock, mock_exists: MagicMock, mock_diag: MagicMock
+    ) -> None:
+        """Should skip the own rootless socket in glob scan (already tried)."""
+        # Host fails, own rootless fails, alt rootless also fails, dockerd fails
+        mock_ready.side_effect = [False, False, False, False, False, False]
+        own_sock = f"/run/user/{os.getuid()}/docker.sock"
+        alt_sock = "/run/user/999/docker.sock"
+        with (
+            patch("devx.molecule.start_docker.glob.glob", return_value=[own_sock, alt_sock]),
+            patch("devx.molecule.start_docker.time.sleep"),
+            patch("devx.molecule.start_docker.subprocess.Popen"),
+            patch("devx.molecule.start_docker.tempfile.NamedTemporaryFile") as mock_ntf,
+            patch("builtins.open", mock_open(read_data="err")),
+        ):
+            mock_ntf.return_value = MagicMock(name="/tmp/dockerd.log")
+            assert start_docker_daemon(timeout=2) is False
+
+    @patch("devx.molecule.start_docker.glob.glob", return_value=[])
     @patch("devx.molecule.start_docker._diagnose_socket")
     @patch("devx.molecule.start_docker.os.path.exists", return_value=False)
     @patch("devx.molecule.start_docker.is_docker_ready", return_value=False)
@@ -92,6 +140,7 @@ class TestStartDockerDaemon:
         mock_ready: MagicMock,
         mock_exists: MagicMock,
         mock_diag: MagicMock,
+        mock_glob: MagicMock,
     ) -> None:
         mock_ntf.return_value = MagicMock(name="/tmp/dockerd.log")
         # Host fails, rootless doesn't exist, local daemon starts
@@ -104,6 +153,7 @@ class TestStartDockerDaemon:
         assert "vfs" in popen_args
         assert "-H" in popen_args
 
+    @patch("devx.molecule.start_docker.glob.glob", return_value=[])
     @patch("devx.molecule.start_docker._diagnose_socket")
     @patch("devx.molecule.start_docker.os.path.exists", return_value=False)
     @patch("devx.molecule.start_docker.is_docker_ready", return_value=False)
@@ -118,6 +168,7 @@ class TestStartDockerDaemon:
         mock_ready: MagicMock,
         mock_exists: MagicMock,
         mock_diag: MagicMock,
+        mock_glob: MagicMock,
     ) -> None:
         mock_ntf.return_value = MagicMock(name="/tmp/dockerd.log")
         with patch("builtins.open", mock_open(read_data="dockerd error log")):
@@ -125,6 +176,7 @@ class TestStartDockerDaemon:
         mock_popen.assert_called_once()
         assert mock_sleep.call_count == 3
 
+    @patch("devx.molecule.start_docker.glob.glob", return_value=[])
     @patch("devx.molecule.start_docker._diagnose_socket")
     @patch("devx.molecule.start_docker.os.path.exists", return_value=False)
     @patch("devx.molecule.start_docker.is_docker_ready", return_value=False)
@@ -139,12 +191,14 @@ class TestStartDockerDaemon:
         mock_ready: MagicMock,
         mock_exists: MagicMock,
         mock_diag: MagicMock,
+        mock_glob: MagicMock,
     ) -> None:
         """Should handle log read errors gracefully."""
         mock_ntf.return_value = MagicMock(name="/tmp/dockerd.log")
         with patch("builtins.open", side_effect=OSError("permission denied")):
             assert start_docker_daemon(timeout=2) is False
 
+    @patch("devx.molecule.start_docker.glob.glob", return_value=[])
     @patch("devx.molecule.start_docker._diagnose_socket")
     @patch("devx.molecule.start_docker.os.path.exists", return_value=False)
     @patch("devx.molecule.start_docker.is_docker_ready")
@@ -159,6 +213,7 @@ class TestStartDockerDaemon:
         mock_ready: MagicMock,
         mock_exists: MagicMock,
         mock_diag: MagicMock,
+        mock_glob: MagicMock,
     ) -> None:
         mock_ntf.return_value = MagicMock(name="/tmp/dockerd.log")
         # Host fails, rootless doesn't exist, local ready on first loop check