Re-organize metrics resource

synapse/metrics/__init__.py

@@ -41,19 +41,27 @@ from typing import (
 )
 
 import attr
-from prometheus_client import CollectorRegistry, Counter, Gauge, Histogram, Metric
-from prometheus_client.core import (
+from prometheus_client import (
     REGISTRY,
+    CollectorRegistry,
+    Counter,
+    Gauge,
+    Histogram,
+    Metric,
+    generate_latest,
+)
+from prometheus_client.core import (
     GaugeHistogramMetricFamily,
     GaugeMetricFamily,
 )
 
 from twisted.python.threadpool import ThreadPool
+from twisted.web.resource import Resource
+from twisted.web.server import Request
 
 # This module is imported for its side effects; flake8 needn't warn that it's unused.
 import synapse.metrics._reactor_metrics  # noqa: F401
 from synapse.metrics._gc import MIN_TIME_BETWEEN_GCS, install_gc_manager
-from synapse.metrics._twisted_exposition import MetricsResource, generate_latest
 from synapse.metrics._types import Collector
 from synapse.types import StrSequence
 from synapse.util import SYNAPSE_VERSION
@@ -66,6 +74,35 @@ all_gauges: Dict[str, Collector] = {}
 
 HAVE_PROC_SELF_STAT = os.path.exists("/proc/self/stat")
 
+CONTENT_TYPE_LATEST = "text/plain; version=0.0.4; charset=utf-8"
+
+
+def _set_prometheus_client_use_created_metrics(new_value: bool) -> None:
+    """
+    Sets whether prometheus_client should expose `_created`-suffixed metrics for
+    all gauges, histograms and summaries.
+
+    There is no programmatic way in the old versions of `prometheus_client` to disable
+    this without poking at internals; the proper way in the old `prometheus_client`
+    versions is to use an environment variable which prometheus_client loads at import
+    time OR to use the dedicated `disable_created_metrics()`/`enable_created_metrics()`
+    functions, but these were only added in `prometheus_client` `0.18.0`.
+
+    The motivation for disabling these `_created` metrics is that they're
+    a waste of space as they're not useful but they take up space in Prometheus.
+    """
+    import prometheus_client.metrics
+
+    if hasattr(prometheus_client.metrics, "_use_created"):
+        prometheus_client.metrics._use_created = new_value
+    else:
+        logger.error(
+            "Can't disable `_created` metrics in prometheus_client (brittle hack broken?)"
+        )
+
+
+_set_prometheus_client_use_created_metrics(False)
+
 
 class _RegistryProxy:
     @staticmethod
@@ -474,6 +511,23 @@ def register_threadpool(name: str, threadpool: ThreadPool) -> None:
     )
 
 
+class MetricsResource(Resource):
+    """
+    Twisted ``Resource`` that serves prometheus metrics.
+    """
+
+    isLeaf = True
+
+    def __init__(self, registry: CollectorRegistry = REGISTRY):
+        self.registry = registry
+
+    def render_GET(self, request: Request) -> bytes:
+        request.setHeader(b"Content-Type", CONTENT_TYPE_LATEST.encode("ascii"))
+        response = generate_latest(self.registry)
+        request.setHeader(b"Content-Length", str(len(response)))
+        return response
+
+
 __all__ = [
     "Collector",
     "MetricsResource",

synapse/metrics/_twisted_exposition.py

@@ -1,80 +0,0 @@
-#
-# This file is licensed under the Affero General Public License (AGPL) version 3.
-#
-# Copyright 2019 Matrix.org Foundation C.I.C.
-# Copyright 2015-2019 Prometheus Python Client Developers
-# Copyright (C) 2023 New Vector, Ltd
-#
-# This program is free software: you can redistribute it and/or modify
-# it under the terms of the GNU Affero General Public License as
-# published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# See the GNU Affero General Public License for more details:
-# <https://www.gnu.org/licenses/agpl-3.0.html>.
-#
-# Originally licensed under the Apache License, Version 2.0:
-# <http://www.apache.org/licenses/LICENSE-2.0>.
-#
-# [This file includes modifications made by New Vector Limited]
-#
-#
-
-import logging
-
-from prometheus_client import (
-    REGISTRY,
-    CollectorRegistry,
-    generate_latest,
-)
-
-from twisted.web.resource import Resource
-from twisted.web.server import Request
-
-logger = logging.getLogger(__name__)
-
-CONTENT_TYPE_LATEST = "text/plain; version=0.0.4; charset=utf-8"
-
-
-def _set_prometheus_client_use_created_metrics(new_value: bool) -> None:
-    """
-    Sets whether prometheus_client should expose `_created`-suffixed metrics for
-    all gauges, histograms and summaries.
-
-    There is no programmatic way in the old versions of `prometheus_client` to disable
-    this without poking at internals; the proper way in the old `prometheus_client`
-    versions is to use an environment variable which prometheus_client loads at import
-    time OR to use the dedicated `disable_created_metrics()`/`enable_created_metrics()`
-    functions, but these were only added in `prometheus_client` `0.18.0`.
-
-    The motivation for disabling these `_created` metrics is that they're
-    a waste of space as they're not useful but they take up space in Prometheus.
-    """
-    import prometheus_client.metrics
-
-    if hasattr(prometheus_client.metrics, "_use_created"):
-        prometheus_client.metrics._use_created = new_value
-    else:
-        logger.error(
-            "Can't disable `_created` metrics in prometheus_client (brittle hack broken?)"
-        )
-
-
-_set_prometheus_client_use_created_metrics(False)
-
-
-class MetricsResource(Resource):
-    """
-    Twisted ``Resource`` that serves prometheus metrics.
-    """
-
-    isLeaf = True
-
-    def __init__(self, registry: CollectorRegistry = REGISTRY):
-        self.registry = registry
-
-    def render_GET(self, request: Request) -> bytes:
-        request.setHeader(b"Content-Type", CONTENT_TYPE_LATEST.encode("ascii"))
-        response = generate_latest(self.registry)
-        request.setHeader(b"Content-Length", str(len(response)))
-        return response

synapse/util/metrics.py

@@ -46,6 +46,7 @@ from synapse.util import Clock
 
 logger = logging.getLogger(__name__)
 
+
 block_counter = Counter("synapse_util_metrics_block_count", "", ["block_name"])
 
 block_timer = Counter("synapse_util_metrics_block_time_seconds", "", ["block_name"])

tests/storage/test_event_metrics.py

@@ -18,9 +18,8 @@
 # [This file includes modifications made by New Vector Limited]
 #
 #
-from prometheus_client import generate_latest
 
-from synapse.metrics import REGISTRY
+from synapse.metrics import REGISTRY, generate_latest
 from synapse.types import UserID, create_requester
 
 from tests.unittest import HomeserverTestCase