DEVX-14: feat: fix molecule platforms to use sleep infinity, add --platforms-file

.taskid

@@ -1 +1 @@
-DEVX-13
+DEVX-14

src/devx/molecule/distribute_molecule.py

@@ -25,7 +25,7 @@ from pathlib import Path
 import click
 
 from devx.i18n import _
-from devx.molecule.platforms import PLATFORMS
+from devx.molecule.platforms import PLATFORMS, load_platforms
 
 DEFAULT_MAX_RUNNERS = 3
 MOLECULE_ROOT = Path("ansible/roles/gitea-runner/molecule")
@@ -238,6 +238,13 @@ def _write_github_env(key: str, value: str) -> None:
     help="Roles directory for multi-role discovery (scans */molecule/*/). "
     "Use this for projects with multiple Ansible roles. Default: disabled (single-role mode).",
 )
+@click.option(
+    "--platforms-file",
+    type=click.Path(exists=True, file_okay=True, path_type=Path),
+    default=None,
+    help="JSON file with custom platform list (each entry: name, image, command). "
+    "Overrides the default platform matrix. Useful for projects with custom test images.",
+)
 def cli(
     runner_index: int | None,
     max_runners: int,
@@ -247,7 +254,9 @@ def cli(
     skip_if_excess: bool,
     molecule_root: Path | None,
     roles_root: Path | None,
+    platforms_file: Path | None,
 ) -> None:
+    platforms = load_platforms(platforms_file)
     # Multi-role mode: discover (role, scenario) pairs across all roles
     if roles_root is not None:
         role_scenarios = discover_multi_role_scenarios(roles_root)
@@ -256,10 +265,10 @@ def cli(
                 click.echo(f"{role}|{scenario}")
             return
         if list_platforms:
-            for p in PLATFORMS:
+            for p in platforms:
                 click.echo(f"{p['name']}|{p['image']}|{p['command']}")
             return
-        pairs_mr = build_multi_role_pairs(role_scenarios)
+        pairs_mr = build_multi_role_pairs(role_scenarios, platforms)
         if runner_index is None:
             groups = distribute_multi_role(pairs_mr, max_runners)
             for i, group in enumerate(groups):
@@ -291,10 +300,10 @@ def cli(
             click.echo(s)
         return
     if list_platforms:
-        for p in PLATFORMS:
+        for p in platforms:
             click.echo(f"{p['name']}|{p['image']}|{p['command']}")
         return
-    pairs = build_pairs(scenarios)
+    pairs = build_pairs(scenarios, platforms)
     if runner_index is None:
         groups = distribute(pairs, max_runners)
         for i, group in enumerate(groups):

src/devx/molecule/platforms.py

@@ -10,13 +10,39 @@ dev tools and CI scripts.
 
 from __future__ import annotations
 
-#: Supported OS platform matrix.
+import json
+from pathlib import Path
+
+#: Default supported OS platform matrix.
 #: Each entry maps a short name to (image, command).
-#: The command must be systemd since rootless Docker requires
-#: loginctl/systemctl --user.
+#: Uses the project's pre-built molecule-test-base image with
+#: ``sleep infinity`` (NOT systemd) to avoid cgroup v2 failures.
 PLATFORMS: list[dict[str, str]] = [
-    {"name": "ubuntu-2204", "image": "geerlingguy/docker-ubuntu2204-ansible:latest", "command": "/lib/systemd/systemd"},
-    {"name": "ubuntu-2404", "image": "geerlingguy/docker-ubuntu2404-ansible:latest", "command": "/lib/systemd/systemd"},
-    {"name": "debian-12", "image": "geerlingguy/docker-debian12-ansible:latest", "command": "/lib/systemd/systemd"},
-    {"name": "archlinux", "image": "marcstraube/archlinux-ansible:latest", "command": "/usr/lib/systemd/systemd"},
+    {
+        "name": "ubuntu-2604",
+        "image": "git.oblachno.oblachno.fyi/oblachno/molecule-test-base:latest",
+        "command": "sleep infinity",
+    },
 ]
+
+
+def load_platforms(platforms_file: str | Path | None = None) -> list[dict[str, str]]:
+    """Load platforms from a JSON file, falling back to PLATFORMS.
+
+    Args:
+        platforms_file: Path to a JSON file with a list of platform dicts.
+            Each dict must have ``name``, ``image``, and ``command`` keys.
+
+    Returns:
+        List of platform dictionaries.
+    """
+    if platforms_file is None:
+        return PLATFORMS
+    path = Path(platforms_file)
+    if not path.is_file():
+        return PLATFORMS
+    with path.open() as f:
+        data = json.load(f)
+    if not isinstance(data, list) or not data:
+        return PLATFORMS
+    return data

tests/unit/test_distribute_molecule.py

@@ -163,10 +163,7 @@ class TestCli:
             runner = CliRunner()
             result = runner.invoke(cli, ["--list-platforms"])
         assert result.exit_code == 0
-        assert "ubuntu-2204" in result.output
-        assert "ubuntu-2404" in result.output
-        assert "debian-12" in result.output
-        assert "archlinux" in result.output
+        assert "ubuntu-2604" in result.output
 
     def test_no_runner_index_prints_all_groups(self, tmp_path: Path) -> None:
         from click.testing import CliRunner
@@ -198,7 +195,7 @@ class TestCli:
             assert result.exit_code == 0
             # Output should contain encoded pairs with platform info
             assert "alpha|" in result.output
-            assert "ubuntu-2204" in result.output
+            assert "ubuntu-2604" in result.output
 
 
 class TestGithubEnv:
@@ -409,7 +406,7 @@ class TestCliMultiRole:
         runner = CliRunner()
         result = runner.invoke(cli, ["--roles-root", str(roles), "--list-platforms"])
         assert result.exit_code == 0
-        assert "ubuntu-2204" in result.output
+        assert "ubuntu-2604" in result.output
 
     def test_roles_root_no_runner_index_prints_groups(self, tmp_path: Path) -> None:
         """--roles-root without --runner-index prints all groups."""
@@ -422,6 +419,27 @@ class TestCliMultiRole:
         assert "Runner 0:" in result.output
         assert "Runner 1:" in result.output
 
+    def test_platforms_file_overrides_default(self, tmp_path: Path) -> None:
+        """--platforms-file loads custom platforms from JSON."""
+        import json
+
+        from click.testing import CliRunner
+
+        from devx.molecule.distribute_molecule import cli
+
+        roles = tmp_path / "roles"
+        (roles / "role-a" / "molecule" / "default").mkdir(parents=True)
+        platforms_file = tmp_path / "platforms.json"
+        custom = [{"name": "custom-os", "image": "custom:latest", "command": "sleep infinity"}]
+        platforms_file.write_text(json.dumps(custom))
+        runner = CliRunner()
+        result = runner.invoke(
+            cli, ["--roles-root", str(roles), "--platforms-file", str(platforms_file), "--list-platforms"]
+        )
+        assert result.exit_code == 0
+        assert "custom-os" in result.output
+        assert "custom:latest" in result.output
+
     def test_roles_root_skips_non_dir_role(self, tmp_path: Path) -> None:
         """Non-directory entries in roles root are skipped."""
         roles = tmp_path / "roles"

tests/unit/test_platforms.py

@@ -1,11 +1,13 @@
-"""Unit tests for scripts/ci/platforms.py."""
+"""Unit tests for devx.molecule.platforms."""
 
-from devx.molecule.platforms import PLATFORMS
+import json
+
+from devx.molecule.platforms import PLATFORMS, load_platforms
 
 
 class TestPlatforms:
     def test_platforms_not_empty(self) -> None:
-        assert len(PLATFORMS) >= 4
+        assert len(PLATFORMS) >= 1
 
     def test_each_platform_has_required_keys(self) -> None:
         for p in PLATFORMS:
@@ -17,9 +19,40 @@ class TestPlatforms:
         names = [p["name"] for p in PLATFORMS]
         assert len(names) == len(set(names))
 
+    def test_platforms_use_sleep_infinity(self) -> None:
+        """All default platforms must use sleep infinity, not systemd."""
+        for p in PLATFORMS:
+            assert p["command"] == "sleep infinity", f"Platform {p['name']} uses {p['command']}"
+
     def test_known_platforms_present(self) -> None:
         names = {p["name"] for p in PLATFORMS}
-        assert "ubuntu-2204" in names
-        assert "ubuntu-2404" in names
-        assert "debian-12" in names
-        assert "archlinux" in names
+        assert "ubuntu-2604" in names
+
+
+class TestLoadPlatforms:
+    def test_load_platforms_default(self, tmp_path) -> None:  # type: ignore[no-untyped-def]
+        """load_platforms with no file returns PLATFORMS."""
+        result = load_platforms(None)
+        assert result == PLATFORMS
+
+    def test_load_platforms_from_file(self, tmp_path) -> None:  # type: ignore[no-untyped-def]
+        """load_platforms reads custom platforms from JSON file."""
+        custom = [
+            {"name": "custom-os", "image": "custom:latest", "command": "sleep infinity"},
+        ]
+        f = tmp_path / "platforms.json"
+        f.write_text(json.dumps(custom))
+        result = load_platforms(f)
+        assert result == custom
+
+    def test_load_platforms_missing_file_falls_back(self, tmp_path) -> None:  # type: ignore[no-untyped-def]
+        """load_platforms falls back to PLATFORMS when file doesn't exist."""
+        result = load_platforms(tmp_path / "nonexistent.json")
+        assert result == PLATFORMS
+
+    def test_load_platforms_empty_list_falls_back(self, tmp_path) -> None:  # type: ignore[no-untyped-def]
+        """load_platforms falls back to PLATFORMS when file has empty list."""
+        f = tmp_path / "platforms.json"
+        f.write_text("[]")
+        result = load_platforms(f)
+        assert result == PLATFORMS