Initial commit

enroll/systemd.py

@@ -0,0 +1,90 @@
+from __future__ import annotations
+
+import re
+import subprocess
+from dataclasses import dataclass
+from typing import List, Optional
+
+
+@dataclass
+class UnitInfo:
+    name: str
+    fragment_path: Optional[str]
+    dropin_paths: List[str]
+    env_files: List[str]
+    exec_paths: List[str]  # binaries from ExecStart "path=" parts
+
+
+class UnitQueryError(RuntimeError):
+    def __init__(self, unit: str, stderr: str):
+        self.unit = unit
+        self.stderr = (stderr or "").strip()
+        super().__init__(f"systemctl show failed for {unit}: {self.stderr}")
+
+
+def _run(cmd: list[str]) -> str:
+    p = subprocess.run(cmd, check=False, text=True, capture_output=True)
+    if p.returncode != 0:
+        raise RuntimeError(f"Command failed: {cmd}\n{p.stderr}")
+    return p.stdout
+
+
+def list_enabled_services() -> List[str]:
+    out = _run(["systemctl", "list-unit-files", "--type=service", "--state=enabled", "--no-legend"])
+    units: List[str] = []
+    for line in out.splitlines():
+        parts = line.split()
+        if not parts:
+            continue
+        unit = parts[0].strip()
+        if not unit.endswith(".service"):
+            continue
+        # Skip template units like "getty@.service" which are enabled but not valid for systemctl show
+        if unit.endswith("@.service") or "@.service" in unit:
+            continue
+        units.append(unit)
+    return sorted(set(units))
+
+
+def get_unit_info(unit: str) -> UnitInfo:
+    p = subprocess.run(
+        [
+            "systemctl", "show", unit,
+            "-p", "FragmentPath",
+            "-p", "DropInPaths",
+            "-p", "EnvironmentFiles",
+            "-p", "ExecStart",
+            "--no-page",
+        ],
+        check=False,
+        text=True,
+        capture_output=True,
+    )
+    if p.returncode != 0:
+        raise UnitQueryError(unit, p.stderr)
+
+    kv: dict[str, str] = {}
+    for line in (p.stdout or "").splitlines():
+        if "=" in line:
+            k, v = line.split("=", 1)
+            kv[k] = v.strip()
+
+    fragment = kv.get("FragmentPath") or None
+
+    dropins = [pp for pp in (kv.get("DropInPaths", "") or "").split() if pp]
+
+    env_files: List[str] = []
+    for token in (kv.get("EnvironmentFiles", "") or "").split():
+        token = token.lstrip("-")
+        if token:
+            env_files.append(token)
+
+    exec_paths = re.findall(r"path=([^ ;}]+)", kv.get("ExecStart", "") or "")
+
+    return UnitInfo(
+        name=unit,
+        fragment_path=fragment,
+        dropin_paths=sorted(set(dropins)),
+        env_files=sorted(set(env_files)),
+        exec_paths=sorted(set(exec_paths)),
+    )