feat: reboot_host (0.5.0)

HostRebootMixin's reboot_host over the command channel: reboot detached
and two seconds late, so the answer comes back before the session goes
down, and a refusal is raised instead of being mistaken for the dropped
session. netOrk sent /sbin/reboot through the private _send_command and
could not tell the two apart (netOrk #1113). A login other than root is
refused before anything runs.

napalm_openwrt/openwrt.py

@@ -65,6 +65,11 @@ def _sources(settings: dict) -> list[str]:
     ]
 
 
+#: ``reboot`` detached from the session and two seconds late: the answer comes
+#: back first, and a hang-up from the closing session does not stop it.
+_REBOOT_DETACHED = "sh -c '(trap \"\" HUP; sleep 2; reboot) </dev/null >/dev/null 2>&1 &'"
+
+
 class OpenWrtDriver(
     OpenWrtInterfaceMixin,
     OpenWrtVLANMixin,
@@ -223,6 +228,22 @@ class OpenWrtDriver(
         self._check_privilege(privileged)
         return open_stream_on_transport(self._transport(), command)
 
+    def reboot_host(self) -> None:
+        """Restart the AP (``HostRebootMixin``); returns once the restart is under way.
+
+        Detached and two seconds late, so the answer comes back before the
+        session goes down; a refusal is raised, not mistaken for that.
+
+        :raises RuntimeError: for a login other than root, or a refused reboot.
+        """
+        try:
+            result = self.run_command(_REBOOT_DETACHED, privileged=True, timeout=30)
+        except PermissionError as exc:
+            raise RuntimeError(str(exc)) from exc
+        if result.exit_code:
+            reason = result.stderr.strip() or result.stdout.strip()
+            raise RuntimeError(reason or f"reboot exited with status {result.exit_code}")
+
     def _run_listening_sockets_command(self, command: str, *, privileged: bool) -> str:
         """Run the listening-socket command for ``ListeningSocketsMixin``.