feat!: report the package proxy as a fact; no warnings of its own (0.9.0)

get_device_warnings decided two things for the application: that any
pending update is a warning (it re-read the updates for that), and
whether apt's proxy is the one the application's setting wants, which
it was handed as optional_args["apt_proxy_url"].

The driver reports facts instead (napalm-device-types 4.14):
get_package_proxy() says which proxy apt fetches through, None for none
or on a non-apt host; the updates are get_available_updates() as
before. get_device_warnings and the apt_proxy_url argument go.

BREAKING CHANGE: get_device_warnings and optional_args["apt_proxy_url"]
are removed. Requires napalm-device-types 4.14.

Closes #28

tests/test_fix_templates.py

@@ -211,3 +211,26 @@ class TestManagementPeer:
     @pytest.mark.parametrize("answer", ["", "\n", "garbage", "not-an-ip 1 2 3"])
     def test_nothing_usable_is_none(self, answer):
         assert self._driver(answer).get_management_peer() is None
+
+
+class TestFactsNotWarnings:
+    """The driver reports facts; the application names warnings (#28, netOrk #1111)."""
+
+    def test_no_warnings_of_its_own(self):
+        assert "get_device_warnings" not in vars(LinuxDriver)
+
+    def test_the_package_proxy_apt_fetches_through(self, driver):
+        driver._send = lambda command, read_timeout=100: 'Acquire::http::Proxy "http://c:3142";'
+        assert driver.get_package_proxy() == "http://c:3142"
+
+    def test_no_proxy_set(self, driver):
+        driver._send = lambda command, read_timeout=100: ""
+        assert driver.get_package_proxy() is None
+
+    def test_not_an_apt_host(self, driver):
+        driver._pkg_manager = "dnf"
+        assert driver.get_package_proxy() is None
+
+    def test_the_applications_proxy_url_is_no_argument_any_more(self):
+        d = LinuxDriver("h", "admin", "p", optional_args={"apt_proxy_url": "http://c:3142"})
+        assert not hasattr(d, "_apt_proxy_url")

tests/test_staged_root_writes.py

@@ -123,7 +123,7 @@ def _driver(host: Host) -> LinuxDriver:
         "h",
         "admin",
         "p",
-        optional_args={"sudo_password": _PW, "apt_proxy_url": "http://proxy:3142"},
+        optional_args={"sudo_password": _PW},
     )
     driver._device = MagicMock()
     driver._device.send_command.side_effect = _shell