opentelemetry-exporter-otlp-proto-http: auto-append signal path when base URL is passed as endpoint

.changelog/5273.added

@@ -0,0 +1 @@
+`opentelemetry-exporter-otlp-proto-http`: auto-append signal path when a base URL (no path or path `/`) is passed as `endpoint` to HTTP OTLP exporters

exporter/opentelemetry-exporter-otlp-proto-http/src/opentelemetry/exporter/otlp/proto/http/_common/__init__.py

@@ -3,6 +3,7 @@
 
 from os import environ
 from typing import Literal
+from urllib.parse import urlparse, urlunparse
 
 import requests
 
@@ -12,6 +13,19 @@
 from opentelemetry.util._importlib_metadata import entry_points
 
 
+def _resolve_endpoint_to_signal(endpoint: str, signal_path: str) -> str:
+    """Append signal_path to endpoint if it has no signal-specific path.
+
+    Uses proper URL manipulation so query strings and fragments are preserved.
+    If the endpoint already has a path other than '/', it is returned unchanged.
+    """
+    parsed = urlparse(endpoint)
+    if not parsed.path or parsed.path == "/":
+        base = parsed.path.rstrip("/")
+        return urlunparse(parsed._replace(path=f"{base}/{signal_path}"))
+    return endpoint
+
+
 def _is_retryable(resp: requests.Response) -> bool:
     if resp.status_code == 408:
         return True

exporter/opentelemetry-exporter-otlp-proto-http/src/opentelemetry/exporter/otlp/proto/http/_log_exporter/__init__.py

@@ -27,6 +27,7 @@
 from opentelemetry.exporter.otlp.proto.http._common import (
     _is_retryable,
     _load_session_from_envvar,
+    _resolve_endpoint_to_signal,
 )
 from opentelemetry.metrics import MeterProvider
 from opentelemetry.sdk._logs import ReadableLogRecord
@@ -88,12 +89,17 @@ def __init__(
         meter_provider: MeterProvider | None = None,
     ):
         self._shutdown_is_occuring = threading.Event()
-        self._endpoint = endpoint or environ.get(
-            OTEL_EXPORTER_OTLP_LOGS_ENDPOINT,
-            _append_logs_path(
-                environ.get(OTEL_EXPORTER_OTLP_ENDPOINT, DEFAULT_ENDPOINT)
-            ),
-        )
+        if endpoint is not None:
+            self._endpoint = _resolve_endpoint_to_signal(
+                endpoint, DEFAULT_LOGS_EXPORT_PATH
+            )
+        else:
+            self._endpoint = environ.get(
+                OTEL_EXPORTER_OTLP_LOGS_ENDPOINT,
+                _append_logs_path(
+                    environ.get(OTEL_EXPORTER_OTLP_ENDPOINT, DEFAULT_ENDPOINT)
+                ),
+            )
         # Keeping these as instance variables because they are used in tests
         self._certificate_file = certificate_file or environ.get(
             OTEL_EXPORTER_OTLP_LOGS_CERTIFICATE,

exporter/opentelemetry-exporter-otlp-proto-http/src/opentelemetry/exporter/otlp/proto/http/metric_exporter/__init__.py

@@ -41,6 +41,7 @@
 from opentelemetry.exporter.otlp.proto.http._common import (
     _is_retryable,
     _load_session_from_envvar,
+    _resolve_endpoint_to_signal,
 )
 from opentelemetry.metrics import MeterProvider
 from opentelemetry.proto.collector.metrics.v1.metrics_service_pb2 import (  # noqa: F401
@@ -147,12 +148,17 @@ def __init__(
                 If it is set and the number of data points exceeds the max, the request will be split.
         """
         self._shutdown_in_progress = threading.Event()
-        self._endpoint = endpoint or environ.get(
-            OTEL_EXPORTER_OTLP_METRICS_ENDPOINT,
-            _append_metrics_path(
-                environ.get(OTEL_EXPORTER_OTLP_ENDPOINT, DEFAULT_ENDPOINT)
-            ),
-        )
+        if endpoint is not None:
+            self._endpoint = _resolve_endpoint_to_signal(
+                endpoint, DEFAULT_METRICS_EXPORT_PATH
+            )
+        else:
+            self._endpoint = environ.get(
+                OTEL_EXPORTER_OTLP_METRICS_ENDPOINT,
+                _append_metrics_path(
+                    environ.get(OTEL_EXPORTER_OTLP_ENDPOINT, DEFAULT_ENDPOINT)
+                ),
+            )
         self._certificate_file = certificate_file or environ.get(
             OTEL_EXPORTER_OTLP_METRICS_CERTIFICATE,
             environ.get(OTEL_EXPORTER_OTLP_CERTIFICATE, True),

exporter/opentelemetry-exporter-otlp-proto-http/src/opentelemetry/exporter/otlp/proto/http/trace_exporter/__init__.py

@@ -29,6 +29,7 @@
 from opentelemetry.exporter.otlp.proto.http._common import (
     _is_retryable,
     _load_session_from_envvar,
+    _resolve_endpoint_to_signal,
 )
 from opentelemetry.metrics import MeterProvider
 from opentelemetry.sdk.environment_variables import (
@@ -84,12 +85,17 @@ def __init__(
         meter_provider: MeterProvider | None = None,
     ):
         self._shutdown_in_progress = threading.Event()
-        self._endpoint = endpoint or environ.get(
-            OTEL_EXPORTER_OTLP_TRACES_ENDPOINT,
-            _append_trace_path(
-                environ.get(OTEL_EXPORTER_OTLP_ENDPOINT, DEFAULT_ENDPOINT)
-            ),
-        )
+        if endpoint is not None:
+            self._endpoint = _resolve_endpoint_to_signal(
+                endpoint, DEFAULT_TRACES_EXPORT_PATH
+            )
+        else:
+            self._endpoint = environ.get(
+                OTEL_EXPORTER_OTLP_TRACES_ENDPOINT,
+                _append_trace_path(
+                    environ.get(OTEL_EXPORTER_OTLP_ENDPOINT, DEFAULT_ENDPOINT)
+                ),
+            )
         self._certificate_file = certificate_file or environ.get(
             OTEL_EXPORTER_OTLP_TRACES_CERTIFICATE,
             environ.get(OTEL_EXPORTER_OTLP_CERTIFICATE, True),

exporter/opentelemetry-exporter-otlp-proto-http/tests/metrics/test_otlp_metrics_exporter.py

@@ -303,6 +303,30 @@ def test_exporter_env_endpoint_with_slash(self):
             OS_ENV_ENDPOINT + f"/{DEFAULT_METRICS_EXPORT_PATH}",
         )
 
+    def test_endpoint_base_url_no_path(self):
+        exporter = OTLPMetricExporter(endpoint="http://collector:4318")
+        self.assertEqual(
+            exporter._endpoint, "http://collector:4318/v1/metrics"
+        )
+
+    def test_endpoint_base_url_trailing_slash(self):
+        exporter = OTLPMetricExporter(endpoint="http://collector:4318/")
+        self.assertEqual(
+            exporter._endpoint, "http://collector:4318/v1/metrics"
+        )
+
+    def test_endpoint_full_url_unchanged(self):
+        exporter = OTLPMetricExporter(
+            endpoint="http://collector:4318/v1/metrics"
+        )
+        self.assertEqual(
+            exporter._endpoint, "http://collector:4318/v1/metrics"
+        )
+
+    def test_endpoint_custom_path_unchanged(self):
+        exporter = OTLPMetricExporter(endpoint="http://collector:4318/custom")
+        self.assertEqual(exporter._endpoint, "http://collector:4318/custom")
+
     @patch.dict(
         "os.environ",
         {

exporter/opentelemetry-exporter-otlp-proto-http/tests/test_proto_log_exporter.py

@@ -259,6 +259,22 @@ def test_exporter_env(self):
         )
         self.assertIsInstance(exporter._session, requests.Session)
 
+    def test_endpoint_base_url_no_path(self):
+        exporter = OTLPLogExporter(endpoint="http://collector:4318")
+        self.assertEqual(exporter._endpoint, "http://collector:4318/v1/logs")
+
+    def test_endpoint_base_url_trailing_slash(self):
+        exporter = OTLPLogExporter(endpoint="http://collector:4318/")
+        self.assertEqual(exporter._endpoint, "http://collector:4318/v1/logs")
+
+    def test_endpoint_full_url_unchanged(self):
+        exporter = OTLPLogExporter(endpoint="http://collector:4318/v1/logs")
+        self.assertEqual(exporter._endpoint, "http://collector:4318/v1/logs")
+
+    def test_endpoint_custom_path_unchanged(self):
+        exporter = OTLPLogExporter(endpoint="http://collector:4318/custom")
+        self.assertEqual(exporter._endpoint, "http://collector:4318/custom")
+
     @staticmethod
     def export_log_and_deserialize(log):
         with patch("requests.Session.post") as mock_post:

exporter/opentelemetry-exporter-otlp-proto-http/tests/test_proto_span_exporter.py

@@ -247,6 +247,31 @@ def test_exporter_env_endpoint_with_slash(self):
             OS_ENV_ENDPOINT + f"/{DEFAULT_TRACES_EXPORT_PATH}",
         )
 
+    def test_endpoint_base_url_no_path(self):
+        exporter = OTLPSpanExporter(endpoint="http://collector:4318")
+        self.assertEqual(exporter._endpoint, "http://collector:4318/v1/traces")
+
+    def test_endpoint_base_url_trailing_slash(self):
+        exporter = OTLPSpanExporter(endpoint="http://collector:4318/")
+        self.assertEqual(exporter._endpoint, "http://collector:4318/v1/traces")
+
+    def test_endpoint_full_url_unchanged(self):
+        exporter = OTLPSpanExporter(endpoint="http://collector:4318/v1/traces")
+        self.assertEqual(exporter._endpoint, "http://collector:4318/v1/traces")
+
+    def test_endpoint_custom_path_unchanged(self):
+        exporter = OTLPSpanExporter(endpoint="http://collector:4318/custom")
+        self.assertEqual(exporter._endpoint, "http://collector:4318/custom")
+
+    def test_endpoint_base_url_with_query_string(self):
+        exporter = OTLPSpanExporter(
+            endpoint="http://collector:4318?tenant=acme"
+        )
+        self.assertEqual(
+            exporter._endpoint,
+            "http://collector:4318/v1/traces?tenant=acme",
+        )
+
     @patch.dict(
         "os.environ",
         {