Merge branch 'main' into pyright-sdk-trace

Author: xrmx

CHANGELOG.md

@@ -24,6 +24,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   ([#4965](https://github.com/open-telemetry/opentelemetry-python/pull/4965))
 - Resolve some Pyright type errors in Span/ReadableSpan and utility stubs
   ([#4973](https://github.com/open-telemetry/opentelemetry-python/pull/4973))
+- `opentelemetry-exporter-prometheus`: Fix metric name prefix
+  ([#4895](https://github.com/open-telemetry/opentelemetry-python/pull/4895))
 
 ## Version 1.40.0/0.61b0 (2026-03-04)
 

docs/conf.py

@@ -202,6 +202,10 @@
     "exclude-members": ",".join(_exclude_members),
 }
 
+# Napoleon configuration to avoid duplication with autodoc for dataclass fields
+# Use ivar (instance variable) style for documenting attributes
+napoleon_use_ivar = True
+
 # -- Options for HTML output -------------------------------------------------
 
 # The theme to use for HTML and HTML Help pages.  See the documentation for

docs/examples/metrics/prometheus-grafana/prometheus-monitor.py

@@ -11,7 +11,7 @@
 start_http_server(port=8000, addr="localhost")
 # Exporter to export metrics to Prometheus
 prefix = "MyAppPrefix"
-reader = PrometheusMetricReader(prefix)
+reader = PrometheusMetricReader(prefix=prefix)
 # Meter is responsible for creating and recording metrics
 set_meter_provider(MeterProvider(metric_readers=[reader]))
 meter = get_meter_provider().get_meter("view-name-change", "0.1.2")

exporter/opentelemetry-exporter-prometheus/src/opentelemetry/exporter/prometheus/__init__.py

@@ -38,7 +38,7 @@
 
     # Exporter to export metrics to Prometheus
     prefix = "MyAppPrefix"
-    reader = PrometheusMetricReader(prefix)
+    reader = PrometheusMetricReader(prefix=prefix)
 
     # Meter is responsible for creating and recording metrics
     set_meter_provider(MeterProvider(metric_readers=[reader]))
@@ -131,7 +131,9 @@ def _convert_buckets(
 class PrometheusMetricReader(MetricReader):
     """Prometheus metric exporter for OpenTelemetry."""
 
-    def __init__(self, disable_target_info: bool = False) -> None:
+    def __init__(
+        self, disable_target_info: bool = False, prefix: str = ""
+    ) -> None:
         super().__init__(
             preferred_temporality={
                 Counter: AggregationTemporality.CUMULATIVE,
@@ -142,9 +144,12 @@ def __init__(self, disable_target_info: bool = False) -> None:
                 ObservableGauge: AggregationTemporality.CUMULATIVE,
             }
         )
-        self._collector = _CustomCollector(disable_target_info)
+        self._collector = _CustomCollector(
+            disable_target_info=disable_target_info, prefix=prefix
+        )
         REGISTRY.register(self._collector)
         self._collector._callback = self.collect
+        self._prefix = prefix
 
     def _receive_metrics(
         self,
@@ -167,11 +172,12 @@ class _CustomCollector:
     https://github.com/prometheus/client_python#custom-collectors
     """
 
-    def __init__(self, disable_target_info: bool = False):
+    def __init__(self, disable_target_info: bool = False, prefix: str = ""):
         self._callback = None
         self._metrics_datas: Deque[MetricsData] = deque()
         self._disable_target_info = disable_target_info
         self._target_info = None
+        self._prefix = prefix
 
     def add_metrics_data(self, metrics_data: MetricsData) -> None:
         """Add metrics to Prometheus data"""
@@ -227,7 +233,10 @@ def _translate_to_prometheus(
             label_values_data_points = []
             values = []
 
-            metric_name = sanitize_full_name(metric.name)
+            metric_name = metric.name
+            if self._prefix:
+                metric_name = self._prefix + "_" + metric_name
+            metric_name = sanitize_full_name(metric_name)
             metric_description = metric.description or ""
             metric_unit = map_unit(metric.unit)
 

exporter/opentelemetry-exporter-prometheus/tests/test_prometheus_exporter.py

@@ -55,7 +55,7 @@ def setUp(self):
         )
 
     def verify_text_format(
-        self, metric: Metric, expect_prometheus_text: str
+        self, metric: Metric, expect_prometheus_text: str, prefix: str = ""
     ) -> None:
         metrics_data = MetricsData(
             resource_metrics=[
@@ -73,7 +73,7 @@ def verify_text_format(
             ]
         )
 
-        collector = _CustomCollector(disable_target_info=True)
+        collector = _CustomCollector(disable_target_info=True, prefix=prefix)
         collector.add_metrics_data(metrics_data)
         result_bytes = generate_latest(collector)
         result = result_bytes.decode("utf-8")
@@ -463,6 +463,30 @@ def test_metric_name(self):
                 """
             ),
         )
+        self.verify_text_format(
+            _generate_sum(name="test_counter_w_prefix", value=1, unit=""),
+            dedent(
+                """\
+                # HELP foo_test_counter_w_prefix_total foo
+                # TYPE foo_test_counter_w_prefix_total counter
+                foo_test_counter_w_prefix_total{a="1",b="true"} 1.0
+                """
+            ),
+            prefix="foo",
+        )
+        self.verify_text_format(
+            _generate_sum(
+                name="test_counter_w_invalid_chars_prefix", value=1, unit=""
+            ),
+            dedent(
+                """\
+                # HELP _foo_test_counter_w_invalid_chars_prefix_total foo
+                # TYPE _foo_test_counter_w_invalid_chars_prefix_total counter
+                _foo_test_counter_w_invalid_chars_prefix_total{a="1",b="true"} 1.0
+                """
+            ),
+            prefix="#foo",
+        )
         self.verify_text_format(
             _generate_sum(name="1leading_digit", value=1, unit=""),
             dedent(

opentelemetry-sdk/src/opentelemetry/sdk/metrics/_internal/__init__.py

@@ -377,13 +377,25 @@ class MeterProvider(APIMeterProvider):
         metric_readers: Register metric readers to collect metrics from the SDK
             on demand. Each :class:`opentelemetry.sdk.metrics.export.MetricReader` is
             completely independent and will collect separate streams of
-            metrics. TODO: reference ``PeriodicExportingMetricReader`` usage with push
-            exporters here.
+            metrics. For push-based export, use
+            :class:`opentelemetry.sdk.metrics.export.PeriodicExportingMetricReader`.
         resource: The resource representing what the metrics emitted from the SDK pertain to.
         shutdown_on_exit: If true, registers an `atexit` handler to call
             `MeterProvider.shutdown`
         views: The views to configure the metric output the SDK
 
+    .. code-block:: python
+        :caption: Push-based export with PeriodicExportingMetricReader
+
+        from opentelemetry.sdk.metrics import MeterProvider
+        from opentelemetry.sdk.metrics.export import (
+            ConsoleMetricExporter,
+            PeriodicExportingMetricReader,
+        )
+
+        reader = PeriodicExportingMetricReader(ConsoleMetricExporter())
+        provider = MeterProvider(metric_readers=[reader])
+
     By default, instruments which do not match any :class:`opentelemetry.sdk.metrics.view.View` (or if no :class:`opentelemetry.sdk.metrics.view.View`\ s
     are provided) will report metrics with the default aggregation for the
     instrument's kind. To disable instruments by default, configure a match-all

opentelemetry-sdk/src/opentelemetry/sdk/metrics/_internal/exemplar/exemplar.py

@@ -26,7 +26,7 @@ class Exemplar:
     was recorded, for example the span and trace ID of the active span when the
     exemplar was recorded.
 
-    Attributes
+    Attributes:
         trace_id: (optional) The trace associated with a recording
         span_id: (optional) The span associated with a recording
         time_unix_nano: The time of the observation
@@ -38,11 +38,6 @@ class Exemplar:
         https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/metrics/sdk.md#exemplar
     """
 
-    # TODO Fix doc - if using valid Google `Attributes:` key, the attributes are duplicated
-    # one will come from napoleon extension and the other from autodoc extension. This
-    # will raise an sphinx error of duplicated object description
-    # See https://github.com/sphinx-doc/sphinx/issues/8664
-
     filtered_attributes: Attributes
     value: Union[int, float]
     time_unix_nano: int

opentelemetry-sdk/src/opentelemetry/sdk/metrics/_internal/measurement.py

@@ -25,19 +25,14 @@ class Measurement:
     """
     Represents a data point reported via the metrics API to the SDK.
 
-    Attributes
+    Attributes:
         value: Measured value
         time_unix_nano: The time the API call was made to record the Measurement
         instrument: The instrument that produced this `Measurement`.
         context: The active Context of the Measurement at API call time.
         attributes: Measurement attributes
     """
 
-    # TODO Fix doc - if using valid Google `Attributes:` key, the attributes are duplicated
-    # one will come from napoleon extension and the other from autodoc extension. This
-    # will raise an sphinx error of duplicated object description
-    # See https://github.com/sphinx-doc/sphinx/issues/8664
-
     value: Union[int, float]
     time_unix_nano: int
     instrument: Instrument