team-3/src/c3nav/mapdata/metrics.py
2024-03-30 22:12:27 +01:00

73 lines
3.2 KiB
Python

import re
from typing import Optional, Sequence
from django.conf import settings
from django.contrib.auth import get_user_model
from django.core.cache import cache
from c3nav.mapdata.models.report import Report
if settings.METRICS:
from prometheus_client import Gauge
from prometheus_client.core import REGISTRY, CounterMetricFamily
from prometheus_client.registry import Collector
users_total = Gauge('c3nav_users_total', 'Total number of users')
users_total.set_function(lambda: get_user_model().objects.count())
reports_total = Gauge('c3nav_reports_total', 'Total number of reports')
reports_total.set_function(lambda: Report.objects.count())
reports_open = Gauge('c3nav_reports_open', 'Number of open reports')
reports_open.set_function(lambda: Report.objects.filter(open=True).count()),
class APIStatsCollector(Collector):
name_registry: dict[str, None | Sequence[str]] = dict()
def collect(self):
metrics: dict[str, CounterMetricFamily] = dict()
if settings.CACHES['default']['BACKEND'] == 'django.core.cache.backends.redis.RedisCache':
client = cache._cache.get_client()
for key in client.keys(f"*{settings.CACHES['default'].get('KEY_PREFIX', '')}apistats__*"):
key: str = key.decode('utf-8').split(':', 2)[2]
value = cache.get(key)
key = key[10:] # trim apistats__ from the beginning
# some routing stats don't use double underscores to separate fields, workaround for now
if key.startswith('route_tuple_'):
key = re.sub(r'^route_tuple_(.*)_(.*)$', r'route_tuple__\1__\2', key)
if key.startswith('route_origin_') or key.startswith('route_destination_'):
key = re.sub(r'^route_(origin|destination)_(.*)$', r'route_\1__\2', key)
name, *labels = key.split('__')
try:
label_names = self.name_registry[name]
except KeyError:
continue
if label_names is None:
label_names = list()
if len(label_names) != len(labels):
raise ValueError('configured labels and number of extracted labels doesn\'t match.')
try:
counter = metrics[name]
except KeyError:
counter = metrics[name] = CounterMetricFamily(f'c3nav_{name}', f'c3nav_{name}',
labels=label_names)
counter.add_metric(labels, value)
return metrics.values()
def describe(self):
return list()
@classmethod
def add_stat(cls, name:str, label_names: Optional[str | Sequence[str]] = None):
if isinstance(label_names, str):
label_names = [label_names]
if name in cls.name_registry and label_names != cls.name_registry[name]:
raise KeyError(f'{name} already exists')
cls.name_registry[name] = label_names
REGISTRY.register(APIStatsCollector())