osm_mon/evaluator/backends/prometheus.py

   1 # -*- coding: utf-8 -*-
   2
   3 # Copyright 2018 Whitestack, LLC
   4 # *************************************************************
   5
   6 # This file is part of OSM Monitoring module
   7 # All Rights Reserved to Whitestack, LLC
   8
   9 # Licensed under the Apache License, Version 2.0 (the "License"); you may
  10 # not use this file except in compliance with the License. You may obtain
  11 # a copy of the License at
  12
  13 #         http://www.apache.org/licenses/LICENSE-2.0
  14
  15 # Unless required by applicable law or agreed to in writing, software
  16 # distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
  17 # WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
  18 # License for the specific language governing permissions and limitations
  19 # under the License.
  20 # For those usages not covered by the Apache License, Version 2.0 please
  21 # contact: bdiaz@whitestack.com or glavado@whitestack.com
  22 ##
  23 import base64
  24 import logging
  25 from typing import Dict, List
  26
  27 import requests
  28
  29 from osm_mon.core.config import Config
  30 from osm_mon.evaluator.backends.base import BaseBackend
  31
  32 log = logging.getLogger(__name__)
  33
  34 OSM_METRIC_PREFIX = "osm_"
  35
  36 DEFAULT_QUERY_METRICS = ["ns_id", "vnf_member_index", "vdu_name"]
  37
  38
  39 class PrometheusBackend(BaseBackend):
  40     def __init__(self, config: Config):
  41         super().__init__(config)
  42         self.conf = config
  43
  44     def get_metric_data(self, metric_name: str, tags: dict):
  45         query = self._build_query(metric_name, tags)
  46         request_url = self._build_url(query)
  47         request_headers = self._build_headers()
  48         return self._query_metric(request_url, request_headers)
  49
  50     def _query_metric(self, request_url: str, headers: Dict[str, str]):
  51         log.info("Querying Prometheus: %s", request_url)
  52         r = requests.get(
  53             request_url,
  54             timeout=int(self.conf.get("global", "request_timeout")),
  55             headers=headers,
  56         )
  57         if r.status_code == 200:
  58             json_response = r.json()
  59             if json_response["status"] == "success":
  60                 return self._get_metric_data_from_response(json_response)
  61             else:
  62                 log.warning(
  63                     "Prometheus response is not success. Got status %s",
  64                     json_response["status"],
  65                 )
  66         else:
  67             log.warning(
  68                 "Error contacting Prometheus. Got status code %s: %s",
  69                 r.status_code,
  70                 r.text,
  71             )
  72         return None
  73
  74     def _build_query(self, metric_name: str, tags: dict) -> str:
  75         query_section_tags = []
  76         for k, v in tags.items():
  77             query_section_tags.append(k + '="' + v + '"')
  78         query_section = "query={0}{{{1}}}".format(
  79             OSM_METRIC_PREFIX + metric_name, ",".join(query_section_tags)
  80         )
  81         return query_section
  82
  83     def _build_url(self, query: str):
  84         return self.conf.get("prometheus", "url") + "/api/v1/query?" + query
  85
  86     def _build_headers(self) -> Dict[str, str]:
  87         headers = {}
  88         user = self.conf.get("prometheus", "user")
  89         password = self.conf.get("prometheus", "password")
  90         if user and password:
  91             _phrase = f"{user}:{password}".encode("utf-8")
  92             token = base64.b64encode(_phrase).decode("utf-8")
  93             headers["Authorization"] = f"Basic {token}"
  94         return headers
  95
  96     def _get_metric_data_from_response(self, json_response) -> List[Dict[str, str]]:
  97         result = json_response["data"]["result"]
  98         metrics_data = []
  99         if len(result):
 100             for metric in result:
 101                 metrics_labels = metric["metric"]
 102                 metric_value = float(metric["value"][1])
 103                 log.info("Metric value: %s", metric_value)
 104                 metrics_data.append({"labels": metrics_labels, "value": metric_value})
 105             return metrics_data
 106         else:
 107             return None