Using admin api, instead open port (#1)

* influxdb2 integration
* using python alpine base image
* add authorization, refactoring config
* logging instead print, keenetic api exception handling when try to collect metrics, a little pep8

keenetic_api.py

@@ -0,0 +1,60 @@
+import hashlib
+from hashlib import sha256
+from typing import Dict
+from urllib import parse
+
+from requests import Session
+
+
+class KeeneticClient:
+
+    def __init__(self, admin_endpoint: str, skip_auth: bool, login: str, password: str):
+        self._admin_endpoint = admin_endpoint
+        self._skip_auth = skip_auth
+        self._login = login
+        self._password = password
+
+    def __enter__(self):
+        self._session = Session()
+        return self
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        if self._session:
+            self._session.close()
+
+    def _auth(self) -> bool:
+        if self._skip_auth:
+            return True
+        auth_endpoint = f"{self._admin_endpoint}/auth"
+        check_auth_response = self._session.get(auth_endpoint)
+        if check_auth_response.status_code == 401:
+            ndm_challenge = check_auth_response.headers.get('X-NDM-Challenge')
+            ndm_realm = check_auth_response.headers.get('X-NDM-Realm')
+            md5 = hashlib.md5((self._login + ':' + ndm_realm + ':' + self._password).encode('utf-8')).hexdigest()
+            sha = sha256((ndm_challenge + md5).encode('utf-8')).hexdigest()
+            auth_response = self._session.post(auth_endpoint, json={'login': self._login, 'password': sha})
+            if auth_response.status_code == 200:
+                return True
+            else:
+                raise ConnectionError(f"Keenetic authorisation failed. Status {auth_response.status_code}")
+        elif check_auth_response.status_code == 200:
+            return True
+        raise ConnectionError(f"Failed to check authorisation, status unknown ({check_auth_response.status_code})")
+
+    def metric(self, command: str, params: Dict) -> Dict:
+        if self._auth():
+            url = f"{self._admin_endpoint}/rci/show/{command.replace(' ', '/')}" + "?" + parse.urlencode(
+                params)
+            r = self._session.get(url)
+            if r.status_code == 200:
+                return r.json()
+            raise KeeneticApiException(r.status_code, r.text)
+        else:
+            raise ConnectionError(f"No keenetic connection.")
+
+
+class KeeneticApiException(Exception):
+
+    def __init__(self, status_code: int, response_text: str):
+        self.status_code = status_code
+        self.response_text = response_text