Hi, I'm interested in this question. Do you have any experience to share?
I'm currently using aioprometheus, but the metric exposure is blocking: https://github.com/claws/aioprometheus/issues/98 Looking at the official client, it seems that they added async ASGI metric exposure. But I don't know if their metrics update will then be blocking. I didn't try it yet. See https://github.com/prometheus/client_python/pull/512 I discover this package but didn't try it yet. https://github.com/Llandy3d/pytheus/issues/55 And there is also this prometheus-async, I asked a question there too: https://github.com/hynek/prometheus-async/issues/59 On Sunday 11 October 2020 at 23:14:34 UTC+1 Alexander wrote: > Is there any way to make custom collector work withing aiohttp application > (or any other way to convert json object to prometheus metrics in aiohttp > application)? > > I'm trying to implement custom collector according to > https://github.com/prometheus/client_python#custom-collectors and > fetching data via *`await session.get(...)`*. The only solution I found > is to change *`def collect()`* method to *`async def collect()`* in > custom collector class and override registry methods with sync loops to > async one and also re-implement *`generate_latest`* function. > > *the overrides:* > ``` > class CustomRegistry(CollectorRegistry): > async def collect(self): > """Yields metrics from the collectors in the registry.""" > collectors = None > ti = None > with self._lock: > collectors = copy.copy(self._collector_to_names) > if self._target_info: > ti = self._target_info_metric() > if ti: > yield ti > for collector in collectors: > async for metric in collector.collect(): > yield metric > > async def register(self, collector): > """Add a collector to the registry.""" > with self._lock: > names = await self._get_names(collector) > duplicates = set(self._names_to_collectors).intersection(names) > if duplicates: > raise ValueError( > 'Duplicated timeseries in CollectorRegistry: > {0}'.format( > duplicates)) > for name in names: > self._names_to_collectors[name] = collector > self._collector_to_names[collector] = names > > async def _get_names(self, collector): > """Get names of timeseries the collector produces.""" > desc_func = None > # If there's a describe function, use it. > try: > desc_func = collector.describe > except AttributeError: > pass > # Otherwise, if auto describe is enabled use the collect function. > if not desc_func and self._auto_describe: > desc_func = collector.collect > > if not desc_func: > return [] > > result = [] > type_suffixes = { > 'counter': ['_total', '_created'], > 'summary': ['', '_sum', '_count', '_created'], > 'histogram': ['_bucket', '_sum', '_count', '_created'], > 'gaugehistogram': ['_bucket', '_gsum', '_gcount'], > 'info': ['_info'], > } > async for metric in desc_func(): > for suffix in type_suffixes.get(metric.type, ['']): > result.append(metric.name + suffix) > return result > > > def sample_line(line): > if line.labels: > labelstr = '{{{0}}}'.format(','.join( > ['{0}="{1}"'.format( > k, v.replace('\\', r'\\').replace('\n', > r'\n').replace('"', r'\"')) > for k, v in sorted(line.labels.items())])) > else: > labelstr = '' > timestamp = '' > if line.timestamp is not None: > # Convert to milliseconds. > timestamp = ' {0:d}'.format(int(float(line.timestamp) * 1000)) > return '{0}{1} {2}{3}\n'.format( > line.name, labelstr, floatToGoString(line.value), timestamp) > > > async def generate_latest(registry): > """Returns the metrics from the registry in latest text format as a > string.""" > output = [] > async for metric in registry.collect(): > try: > mname = metric.name > mtype = metric.type > # Munging from OpenMetrics into Prometheus format. > if mtype == 'counter': > mname = mname + '_total' > elif mtype == 'info': > mname = mname + '_info' > mtype = 'gauge' > elif mtype == 'stateset': > mtype = 'gauge' > elif mtype == 'gaugehistogram': > # A gauge histogram is really a gauge, > # but this captures the structure better. > mtype = 'histogram' > elif mtype == 'unknown': > mtype = 'untyped' > > output.append('# HELP {0} {1}\n'.format( > mname, metric.documentation.replace('\\', > r'\\').replace('\n', r'\n'))) > output.append('# TYPE {0} {1}\n'.format(mname, mtype)) > > om_samples = {} > for s in metric.samples: > for suffix in ['_created', '_gsum', '_gcount']: > if s.name == metric.name + suffix: > # OpenMetrics specific sample, put in a gauge at > the end. > om_samples.setdefault(suffix, > []).append(sample_line(s)) > break > else: > output.append(sample_line(s)) > except Exception as exception: > exception.args = (exception.args or ('',)) + (metric,) > raise > > for suffix, lines in sorted(om_samples.items()): > output.append('# HELP {0}{1} {2}\n'.format(metric.name, > suffix, metric.documentation.replace('\\', r'\\').replace('\n', r'\n'))) > output.append('# TYPE {0}{1} gauge\n'.format(metric.name, > suffix)) > output.extend(lines) > return ''.join(output).encode('utf-8') > ``` > > *the custom collector class:* > ``` > class CustomCollector(object): > def __init__(self, app): > self.session = app['session'] > self.metrics_url = app['metrics_url'] > > async def collect(self): > resp = await self.session.get(self.metrics_url) > payload = await resp.json() > for name, v in payload['metrics'].items(): > name = name.replace('.', '_') > name = name.replace('-', '_') > name = re.sub('(?!^)([A-Z]+)', r'_\1', name).lower() > kind = v['kind'] > if kind == 'Gauge': > m = GaugeMetricFamily(name, name, labels=[]) > if kind == 'Timer': > m = SummaryMetricFamily(name, name, labels=[]) > if kind == 'Counter': > m = CounterMetricFamily(name, name, labels=[]) > for i in v['values']: > tags = i['tags'] > labels = {tag['key']: tag['value'] for tag in tags} > value = i['values'][0]['v'] > timestamp = i['values'][0]['t'] > m.add_sample(name, labels, value, timestamp=timestamp) > yield m > ``` -- You received this message because you are subscribed to the Google Groups "Prometheus Users" group. 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