A simple Prometheus metrics server in python for statistics of website user count

prometheus_metrics.py

#!/usr/bin/env python3
# -*- encoding: utf-8 -*-

import time

from pymongo import MongoClient
from prometheus_client import start_http_server
from prometheus_client.core import GaugeMetricFamily, CounterMetricFamily, REGISTRY

from config.settings import MONGO_USER, MONGO_PASS, MONGO_URL, MONGO_DBNAME

'''
    It is a prometheus exporter，which export website user count to prometheus.
    Prometheus import data by tihs metrics server as a target, and show the user count trending on Grafana.
    In the same way, you can visualize user orders trending, revenue trending, etc....

'''
class CustomCollector(object):

    def __init__(self):
        self.client = MongoClient('mongodb://%s:%s@%s' % (MONGO_USER, MONGO_PASS, MONGO_URL))
        self.db = self.client[MONGO_DBNAME]

    def collect(self):
        users_count = self.db.users.find().count()

        c = CounterMetricFamily('website_user_total', 'total users', labels=['count','users_count'])
        c.add_metric(['users_count'], users_count)

        yield c

if __name__ == '__main__':
    port = 8000
    
    print('starting server http://127.0.0.1:{}/metrics'.format(port))
    REGISTRY.register(CustomCollector())

    # Start up the server to expose the metrics.
    start_http_server(port, addr="127.0.0.1")

    while True:
        time.sleep(3)