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

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