exporter/prometheus_remote_write: sort labels before exporting (#2940)

Author: xrmx

CHANGELOG.md

@@ -34,6 +34,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   ([#2922](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/2922))
 - `opentelemetry-instrumentation-celery` Don't detach context without a None token
   ([#2927](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/2927))
+- `opentelemetry-exporter-prometheus-remote-write`: sort labels before exporting
+  ([#2940](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/2940))
 - `opentelemetry-instrumentation-dbapi` sqlcommenter key values created from PostgreSQL, MySQL systems
   ([#2897](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/2897))
 

exporter/opentelemetry-exporter-prometheus-remote-write/src/opentelemetry/exporter/prometheus_remote_write/__init__.py

@@ -16,7 +16,7 @@
 import re
 from collections import defaultdict
 from itertools import chain
-from typing import Dict, Sequence
+from typing import Dict, Mapping, Sequence
 
 import requests
 import snappy
@@ -253,12 +253,14 @@ def _parse_metric(
         return self._convert_to_timeseries(sample_sets, resource_labels)
 
     def _convert_to_timeseries(
-        self, sample_sets: Sequence[tuple], resource_labels: Sequence
+        self, sample_sets: Mapping[tuple, Sequence], resource_labels: Sequence
     ) -> Sequence[TimeSeries]:
         timeseries = []
         for labels, samples in sample_sets.items():
             ts = TimeSeries()
-            for label_name, label_value in chain(resource_labels, labels):
+            for label_name, label_value in sorted(
+                chain(resource_labels, labels)
+            ):
                 # Previous implementation did not str() the names...
                 ts.labels.append(self._label(label_name, str(label_value)))
             for value, timestamp in samples:

exporter/opentelemetry-exporter-prometheus-remote-write/tests/test_prometheus_remote_write_exporter.py

@@ -22,6 +22,8 @@
     PrometheusRemoteWriteMetricsExporter,
 )
 from opentelemetry.exporter.prometheus_remote_write.gen.types_pb2 import (  # pylint: disable=E0611
+    Label,
+    Sample,
     TimeSeries,
 )
 from opentelemetry.sdk.metrics.export import (
@@ -155,6 +157,38 @@ def test_parse_metric(metric, prom_rw):
             assert sample.value in values
 
 
+def test_convert_to_timeseries(prom_rw):
+    resource_labels = (("service_name", "foo"), ("bool_value", True))
+    sample_sets = {
+        (("foo", "bar"), ("baz", 42), ("__name__", "test_histogram_tu")): [
+            (1, 1641946016139)
+        ],
+        (("baz", "42"), ("foo", "bar")): [(4, 1641946016139)],
+    }
+    timeseries = prom_rw._convert_to_timeseries(sample_sets, resource_labels)
+    assert timeseries == [
+        TimeSeries(
+            labels=[
+                Label(name="__name__", value="test_histogram_tu"),
+                Label(name="baz", value="42"),
+                Label(name="bool_value", value="True"),
+                Label(name="foo", value="bar"),
+                Label(name="service_name", value="foo"),
+            ],
+            samples=[Sample(value=1, timestamp=1641946016139)],
+        ),
+        TimeSeries(
+            labels=[
+                Label(name="baz", value="42"),
+                Label(name="bool_value", value="True"),
+                Label(name="foo", value="bar"),
+                Label(name="service_name", value="foo"),
+            ],
+            samples=[Sample(value=4, timestamp=1641946016139)],
+        ),
+    ]
+
+
 class TestValidation(unittest.TestCase):
     # Test cases to ensure exporter parameter validation works as intended
     def test_valid_standard_param(self):