Add generic labels on metrics using request matchdict fields

kinto/__init__.py

@@ -38,6 +38,7 @@
     "record_id_generator": "kinto.views.RelaxedUUID",
     "project_name": "kinto",
     "admin_assets_path": None,
+    "metrics_matchdict_fields": ["bucket_id", "collection_id", "group_id", "record_id"],
 }
 
 

kinto/core/__init__.py

@@ -96,6 +96,7 @@
     "statsd_backend": "kinto.core.statsd",
     "statsd_prefix": "kinto.core",
     "statsd_url": None,
+    "metrics_matchdict_fields": [],
     "storage_backend": "",
     "storage_url": "",
     "storage_max_fetch_size": 10000,

kinto/core/initialization.py

@@ -481,14 +481,30 @@ def on_new_response(event):
             auth, user_id = user_id.split(":")
             metrics_service.count("users", unique=[("auth", auth), ("userid", user_id)])
 
+        # Add extra labels to metrics, based on fields extracted from the request matchdict.
+        metrics_matchdict_fields = aslist(settings["metrics_matchdict_fields"])
+        # Turn the `id` field of object endpoints into `{resource}_id` (eg. `mushroom_id`, `bucket_id`)
+        enhanced_matchdict = dict(**request.matchdict)
+        try:
+            enhanced_matchdict[request.current_resource_name + "_id"] = enhanced_matchdict.get(
+                "id", ""
+            )
+        except AttributeError:
+            # Not on a resource.
+            pass
+        metrics_matchdict_labels = [
+            (field, enhanced_matchdict.get(field, "")) for field in metrics_matchdict_fields
+        ]
+
         # Count served requests.
         metrics_service.count(
             "request_summary",
             unique=[
                 ("method", request.method.lower()),
                 ("endpoint", utils.strip_uri_prefix(request.path)),
                 ("status", str(request.response.status_code)),
-            ],
+            ]
+            + metrics_matchdict_labels,
         )
 
         try:
@@ -497,7 +513,8 @@ def on_new_response(event):
             metrics_service.observe(
                 "request_duration",
                 duration,
-                labels=[("endpoint", utils.strip_uri_prefix(request.path))],
+                labels=[("endpoint", utils.strip_uri_prefix(request.path))]
+                + metrics_matchdict_labels,
             )
         except AttributeError:  # pragma: no cover
             # Logging was not setup in this Kinto app (unlikely but possible)
@@ -507,7 +524,7 @@ def on_new_response(event):
         metrics_service.observe(
             "request_size",
             len(request.response.body or b""),
-            labels=[("endpoint", utils.strip_uri_prefix(request.path))],
+            labels=[("endpoint", utils.strip_uri_prefix(request.path))] + metrics_matchdict_labels,
         )
 
         # Count authentication verifications.

tests/test_views_metrics.py

@@ -0,0 +1,45 @@
+import unittest
+from unittest import mock
+
+from kinto.core.testing import skip_if_no_prometheus
+
+from .support import BaseWebTest
+
+
+@skip_if_no_prometheus
+class ViewsMetricsTest(BaseWebTest, unittest.TestCase):
+    @classmethod
+    def get_app_settings(cls, extras=None):
+        settings = super().get_app_settings(extras)
+        settings["includes"] += "\nkinto.plugins.prometheus"
+        return settings
+
+    def setUp(self):
+        super().setUp()
+        patch = mock.patch("kinto.plugins.prometheus.PrometheusService")
+        self.mocked = patch.start()
+        self.addCleanup(patch.stop)
+
+    def test_metrics_have_matchdict_labels(self):
+        self.app.put("/buckets/beers", headers=self.headers)
+        self.app.put("/buckets/beers/groups/amateurs", headers=self.headers)
+        self.app.put("/buckets/beers/collections/barley", headers=self.headers)
+        self.app.put("/buckets/beers/collections/barley/records/abc", headers=self.headers)
+
+        resp = self.app.get("/__metrics__")
+        self.assertIn(
+            'request_size_sum{bucket_id="beers",collection_id="",endpoint="/buckets/beers",group_id="",record_id=""}',
+            resp.text,
+        )
+        self.assertIn(
+            'request_size_sum{bucket_id="beers",collection_id="",endpoint="/buckets/beers/groups/amateurs",group_id="amateurs",record_id=""}',
+            resp.text,
+        )
+        self.assertIn(
+            'request_summary_total{bucket_id="beers",collection_id="barley",endpoint="/buckets/beers/collections/barley",group_id="",method="put",record_id="",status="201"}',
+            resp.text,
+        )
+        self.assertIn(
+            'request_duration_sum{bucket_id="beers",collection_id="barley",endpoint="/buckets/beers/collections/barley/records/abc",group_id="",record_id="abc"}',
+            resp.text,
+        )