feat: a public command channel; no warnings of its own (0.4.0)

run_command and open_stream (napalm-device-types CommandChannelMixin,
which AccessPointDriver carries) run on an SSH exec channel next to
netmiko's shell: stdin, stderr apart, a real exit code. netOrk sent UCI
scripts and the wifi channel through the private _send_command, typing
a file in base64 chunks or printf lines; with stdin it writes it with
cat, and base64 is needed for nothing (netOrk #1113). OpenWrt has no
sudo, so a privileged command from a login other than root is refused
before it runs.

get_device_warnings goes with it: no_base64 was its last code.

napalm_openwrt/openwrt.py

@@ -29,10 +29,13 @@ from netmiko.exceptions import NetmikoTimeoutException, NetmikoAuthenticationExc
 
 from napalm_device_types import (
     AccessPointDriver,
+    ByteStream,
+    CommandResult,
     EnsurePackageMixin,
     FingerprintRule,
     SnmpAgentMixin,
 )
+from napalm_device_types.channel import open_stream_on_transport, run_on_transport
 from napalm_device_types.listening import ListeningSocketsMixin
 from napalm.base.exceptions import (
     ConnectionException,
@@ -183,6 +186,43 @@ class OpenWrtDriver(
         except (socket.error, EOFError) as exc:
             raise ConnectionClosedException(str(exc)) from exc
 
+    # ------------------------------------------------------------------
+    # Command channel (napalm-device-types CommandChannelMixin, via AccessPointDriver)
+    # ------------------------------------------------------------------
+
+    def _transport(self) -> Any:
+        """The SSH transport netmiko already holds, for exec channels next to its shell."""
+        if self.device is None:
+            raise ConnectionClosedException("Not connected")
+        return self.device.remote_conn_pre.get_transport()
+
+    def _check_privilege(self, privileged: bool) -> None:
+        if privileged and self.username != "root":
+            raise PermissionError(
+                f"{self.hostname}: OpenWrt has no sudo; {self.username!r} cannot run as root"
+            )
+
+    def run_command(
+        self,
+        command: str,
+        *,
+        privileged: bool = False,
+        timeout: float = 60,
+        stdin: bytes | None = None,
+    ) -> CommandResult:
+        """Run *command* on an SSH exec channel: no PTY, stderr apart, a real exit code.
+
+        The login is root on OpenWrt as a rule, and there is no sudo: a
+        privileged command from any other login is refused before it runs.
+        """
+        self._check_privilege(privileged)
+        return run_on_transport(self._transport(), command, stdin=stdin, timeout=timeout)
+
+    def open_stream(self, command: str, *, privileged: bool = False) -> ByteStream:
+        """Start *command* on an SSH exec channel and return a stream to it."""
+        self._check_privilege(privileged)
+        return open_stream_on_transport(self._transport(), command)
+
     def _run_listening_sockets_command(self, command: str, *, privileged: bool) -> str:
         """Run the listening-socket command for ``ListeningSocketsMixin``.
 

napalm_openwrt/system_mixin.py

@@ -390,19 +390,6 @@ class OpenWrtSystemMixin:
         output = self._send_command(f"/etc/init.d/{name} {action} 2>&1")
         return {"success": True, "output": output}
 
-    def get_device_warnings(self) -> list[dict[str, Any]]:
-        """Only a missing ``base64`` binary, which BusyBox may lack.
-
-        It is not a package the caller can look up -- BusyBox may provide it as
-        an applet -- so it stays here until the shell commands callers send get
-        a public method. lldpd, auc and the pending updates are facts
-        (``get_packages``, ``get_available_updates``); whether they are a
-        problem is the caller's to decide.
-        """
-        if self._send_command("command -v base64 2>/dev/null").strip():
-            return []
-        return [{"code": "no_base64"}]
-
     def get_available_updates(self) -> list[dict[str, Any]]:
         """Return list of upgradable packages from the local package manager cache.