fix: enable systemd lingering for gateway

src/daemon/systemd.ts

@@ -1,5 +1,6 @@
 import { execFile } from "node:child_process";
 import fs from "node:fs/promises";
+import os from "node:os";
 import path from "node:path";
 import { promisify } from "node:util";
 
@@ -7,6 +8,7 @@ import {
   GATEWAY_SYSTEMD_SERVICE_NAME,
   LEGACY_GATEWAY_SYSTEMD_SERVICE_NAMES,
 } from "./constants.js";
+import { runCommandWithTimeout, runExec } from "../process/exec.js";
 
 const execFileAsync = promisify(execFile);
 
@@ -30,6 +32,83 @@ function resolveSystemdUnitPath(
   return resolveSystemdUnitPathForName(env, GATEWAY_SYSTEMD_SERVICE_NAME);
 }
 
+function resolveLoginctlUser(
+  env: Record<string, string | undefined>,
+): string | null {
+  const fromEnv = env.USER?.trim() || env.LOGNAME?.trim();
+  if (fromEnv) return fromEnv;
+  try {
+    return os.userInfo().username;
+  } catch {
+    return null;
+  }
+}
+
+export type SystemdUserLingerStatus = {
+  user: string;
+  linger: "yes" | "no";
+};
+
+export async function readSystemdUserLingerStatus(
+  env: Record<string, string | undefined>,
+): Promise<SystemdUserLingerStatus | null> {
+  const user = resolveLoginctlUser(env);
+  if (!user) return null;
+  try {
+    const { stdout } = await runExec(
+      "loginctl",
+      ["show-user", user, "-p", "Linger"],
+      { timeoutMs: 5_000 },
+    );
+    const line = stdout
+      .split("\n")
+      .map((entry) => entry.trim())
+      .find((entry) => entry.startsWith("Linger="));
+    const value = line?.split("=")[1]?.trim().toLowerCase();
+    if (value === "yes" || value === "no") {
+      return { user, linger: value };
+    }
+  } catch {
+    // ignore; loginctl may be unavailable
+  }
+  return null;
+}
+
+export async function enableSystemdUserLinger(params: {
+  env: Record<string, string | undefined>;
+  user?: string;
+  sudoMode?: "prompt" | "non-interactive";
+}): Promise<{ ok: boolean; stdout: string; stderr: string; code: number }> {
+  const user = params.user ?? resolveLoginctlUser(params.env);
+  if (!user) {
+    return { ok: false, stdout: "", stderr: "Missing user", code: 1 };
+  }
+  const needsSudo =
+    typeof process.getuid === "function" ? process.getuid() !== 0 : true;
+  const sudoArgs =
+    needsSudo && params.sudoMode !== undefined
+      ? ["sudo", ...(params.sudoMode === "non-interactive" ? ["-n"] : [])]
+      : [];
+  const argv = [
+    ...sudoArgs,
+    "loginctl",
+    "enable-linger",
+    user,
+  ];
+  try {
+    const result = await runCommandWithTimeout(argv, { timeoutMs: 30_000 });
+    return {
+      ok: result.code === 0,
+      stdout: result.stdout,
+      stderr: result.stderr,
+      code: result.code ?? 1,
+    };
+  } catch (error) {
+    const message = error instanceof Error ? error.message : String(error);
+    return { ok: false, stdout: "", stderr: message, code: 1 };
+  }
+}
+
 function systemdEscapeArg(value: string): string {
   if (!/[\s"\\]/.test(value)) return value;
   return `"${value.replace(/\\/g, "\\\\").replace(/"/g, '\\"')}"`;