Added Zyxel Keenetic NDMS2 based routers support for device tracking (#9315)

* Added Zyxel Keenetic NDMS2 based routers support for device tracking

* Review feedback

* Review feedback+

* Review feedback: removed unneeded code

.coveragerc

@@ -284,6 +284,7 @@ omit =
     homeassistant/components/device_tracker/gpslogger.py
     homeassistant/components/device_tracker/huawei_router.py
     homeassistant/components/device_tracker/icloud.py
+    homeassistant/components/device_tracker/keenetic_ndms2.py
     homeassistant/components/device_tracker/linksys_ap.py
     homeassistant/components/device_tracker/linksys_smart.py
     homeassistant/components/device_tracker/luci.py

homeassistant/components/device_tracker/keenetic_ndms2.py

@@ -0,0 +1,121 @@
+"""
+Support for Zyxel Keenetic NDMS2 based routers.
+
+For more details about this platform, please refer to the documentation at
+https://home-assistant.io/components/device_tracker.keenetic_ndms2/
+"""
+import logging
+from collections import namedtuple
+
+import requests
+import voluptuous as vol
+
+import homeassistant.helpers.config_validation as cv
+from homeassistant.components.device_tracker import (
+    DOMAIN, PLATFORM_SCHEMA, DeviceScanner)
+from homeassistant.const import (
+    CONF_HOST, CONF_PASSWORD, CONF_USERNAME
+)
+
+_LOGGER = logging.getLogger(__name__)
+
+# Interface name to track devices for. Most likely one will not need to
+# change it from default 'Home'. This is needed not to track Guest WI-FI-
+# clients and router itself
+CONF_INTERFACE = 'interface'
+
+DEFAULT_INTERFACE = 'Home'
+
+
+PLATFORM_SCHEMA = PLATFORM_SCHEMA.extend({
+    vol.Required(CONF_HOST): cv.string,
+    vol.Required(CONF_USERNAME): cv.string,
+    vol.Required(CONF_PASSWORD): cv.string,
+    vol.Required(CONF_INTERFACE, default=DEFAULT_INTERFACE): cv.string,
+})
+
+
+def get_scanner(_hass, config):
+    """Validate the configuration and return a Nmap scanner."""
+    scanner = KeeneticNDMS2DeviceScanner(config[DOMAIN])
+
+    return scanner if scanner.success_init else None
+
+
+Device = namedtuple('Device', ['mac', 'name'])
+
+
+class KeeneticNDMS2DeviceScanner(DeviceScanner):
+    """This class scans for devices using keenetic NDMS2 web interface."""
+
+    def __init__(self, config):
+        """Initialize the scanner."""
+        self.last_results = []
+
+        self._url = 'http://%s/rci/show/ip/arp' % config[CONF_HOST]
+        self._interface = config[CONF_INTERFACE]
+
+        self._username = config.get(CONF_USERNAME)
+        self._password = config.get(CONF_PASSWORD)
+
+        self.success_init = self._update_info()
+        _LOGGER.info("Scanner initialized")
+
+    def scan_devices(self):
+        """Scan for new devices and return a list with found device IDs."""
+        self._update_info()
+
+        return [device.mac for device in self.last_results]
+
+    def get_device_name(self, mac):
+        """Return the name of the given device or None if we don't know."""
+        filter_named = [device.name for device in self.last_results
+                        if device.mac == mac]
+
+        if filter_named:
+            return filter_named[0]
+        return None
+
+    def _update_info(self):
+        """Get ARP from keenetic router."""
+        _LOGGER.info("Fetching...")
+
+        last_results = []
+
+        # doing a request
+        try:
+            from requests.auth import HTTPDigestAuth
+            res = requests.get(self._url, timeout=10, auth=HTTPDigestAuth(
+                self._username, self._password
+            ))
+        except requests.exceptions.Timeout:
+            _LOGGER.error(
+                "Connection to the router timed out at URL %s", self._url)
+            return False
+        if res.status_code != 200:
+            _LOGGER.error(
+                "Connection failed with http code %s", res.status_code)
+            return False
+        try:
+            result = res.json()
+        except ValueError:
+            # If json decoder could not parse the response
+            _LOGGER.error("Failed to parse response from router")
+            return False
+
+        # parsing response
+        for info in result:
+            if info.get('interface') != self._interface:
+                continue
+            mac = info.get('mac')
+            name = info.get('name')
+            # No address = no item :)
+            if mac is None:
+                continue
+
+            last_results.append(Device(mac.upper(), name))
+
+        self.last_results = last_results
+
+        _LOGGER.info("Request successful")
+        return True