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.

tests/unit/test_command_channel.py

@@ -0,0 +1,79 @@
+"""A public command channel (napalm-device-types ``CommandChannelMixin``, netOrk #1113).
+
+netOrk sent UCI scripts and the wifi channel through the private
+``_send_command``: an interactive shell with no exit code, where a file had to
+be typed in base64 chunks or ``printf`` lines. ``run_command`` runs on an SSH
+exec channel of its own, with stdin, stderr and the exit code -- a script is
+written with ``cat`` from stdin, and ``base64`` is needed for nothing.
+"""
+
+from __future__ import annotations
+
+from unittest.mock import MagicMock, patch
+
+import pytest
+from napalm.base.exceptions import ConnectionClosedException
+from napalm_device_types import CommandResult
+
+from napalm_openwrt.openwrt import OpenWrtDriver
+
+
+def _driver(username: str = "root") -> OpenWrtDriver:
+    with patch("napalm_openwrt.openwrt.ConnectHandler"):
+        drv = OpenWrtDriver(hostname="192.0.2.15", username=username, password="")
+    drv.device = MagicMock()
+    return drv
+
+
+def test_a_command_runs_on_the_ssh_transport_with_its_stdin():
+    drv = _driver()
+    transport = drv.device.remote_conn_pre.get_transport.return_value
+    done = CommandResult("", "", 0)
+    with patch("napalm_openwrt.openwrt.run_on_transport", return_value=done) as run:
+        result = drv.run_command("cat > /tmp/x.sh", stdin=b"uci commit\n", timeout=30)
+
+    assert result is done
+    run.assert_called_once_with(transport, "cat > /tmp/x.sh", stdin=b"uci commit\n", timeout=30)
+
+
+def test_root_runs_privileged_commands_as_they_are():
+    drv = _driver()
+    with patch("napalm_openwrt.openwrt.run_on_transport") as run:
+        drv.run_command("wifi", privileged=True)
+
+    assert run.call_args.args[1] == "wifi"
+
+
+def test_a_login_other_than_root_cannot_gain_root():
+    """OpenWrt has no sudo: refused before anything runs, not half done."""
+    drv = _driver(username="admin")
+    with patch("napalm_openwrt.openwrt.run_on_transport") as run, pytest.raises(PermissionError):
+        drv.run_command("wifi", privileged=True)
+
+    run.assert_not_called()
+
+
+def test_a_stream_on_the_same_transport():
+    drv = _driver()
+    transport = drv.device.remote_conn_pre.get_transport.return_value
+    with patch("napalm_openwrt.openwrt.open_stream_on_transport") as stream:
+        drv.open_stream("logread -f")
+
+    stream.assert_called_once_with(transport, "logread -f")
+
+
+def test_not_connected():
+    drv = _driver()
+    drv.device = None
+    with pytest.raises(ConnectionClosedException):
+        drv.run_command("true")
+
+
+def test_no_warnings_of_its_own():
+    """base64 is no longer needed for anything, so a missing one is no warning;
+    lldpd, auc and the updates are facts the caller reads (netOrk #1111)."""
+    assert not any(
+        "get_device_warnings" in vars(c)
+        for c in OpenWrtDriver.__mro__
+        if c.__module__.startswith("napalm_openwrt")
+    )