feat: Open Telemetry Publish Side Support (#1241)

Author: mukund-ananthu

google/cloud/pubsub_v1/open_telemetry/__init__.py

@@ -0,0 +1,13 @@
+# Copyright 2024, Google LLC All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.

google/cloud/pubsub_v1/open_telemetry/context_propagation.py

@@ -0,0 +1,39 @@
+# Copyright 2024, Google LLC All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from opentelemetry.propagators.textmap import Setter
+
+from google.pubsub_v1 import PubsubMessage
+
+
+class OpenTelemetryContextSetter(Setter):
+    """
+    Used by Open Telemetry for context propagation.
+    """
+
+    def set(self, carrier: PubsubMessage, key: str, value: str) -> None:
+        """
+        Injects trace context into Pub/Sub message attributes with
+        "googclient_" prefix.
+
+        Args:
+            carrier(PubsubMessage): The Pub/Sub message which is the carrier of Open Telemetry
+            data.
+            key(str): The key for which the Open Telemetry context data needs to be set.
+            value(str): The Open Telemetry context value to be set.
+
+        Returns:
+            None
+        """
+        carrier.attributes["googclient_" + key] = value

google/cloud/pubsub_v1/open_telemetry/publish_message_wrapper.py

@@ -0,0 +1,142 @@
+# Copyright 2017, Google LLC All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import sys
+from datetime import datetime
+from typing import Optional
+
+from opentelemetry import trace
+from opentelemetry.trace.propagation import set_span_in_context
+from opentelemetry.trace.propagation.tracecontext import TraceContextTextMapPropagator
+
+from google.pubsub_v1 import types as gapic_types
+from google.cloud.pubsub_v1.open_telemetry.context_propagation import (
+    OpenTelemetryContextSetter,
+)
+
+
+class PublishMessageWrapper:
+    _OPEN_TELEMETRY_TRACER_NAME: str = "google.cloud.pubsub_v1"
+    _OPEN_TELEMETRY_MESSAGING_SYSTEM: str = "gcp_pubsub"
+    _OPEN_TELEMETRY_PUBLISHER_BATCHING = "publisher batching"
+
+    _PUBLISH_START_EVENT: str = "publish start"
+    _PUBLISH_FLOW_CONTROL: str = "publisher flow control"
+
+    def __init__(self, message: gapic_types.PubsubMessage):
+        self._message: gapic_types.PubsubMessage = message
+        self._create_span: Optional[trace.Span] = None
+        self._flow_control_span: Optional[trace.Span] = None
+        self._batching_span: Optional[trace.Span] = None
+
+    @property
+    def message(self):
+        return self._message
+
+    @message.setter  # type: ignore[no-redef]  # resetting message value is intentional here
+    def message(self, message: gapic_types.PubsubMessage):
+        self._message = message
+
+    @property
+    def create_span(self):
+        return self._create_span
+
+    def __eq__(self, other):  # pragma: NO COVER
+        """Used for pytest asserts to compare two PublishMessageWrapper objects with the same message"""
+        if isinstance(self, other.__class__):
+            return self.message == other.message
+        return False
+
+    def start_create_span(self, topic: str, ordering_key: str) -> None:
+        tracer = trace.get_tracer(self._OPEN_TELEMETRY_TRACER_NAME)
+        assert len(topic.split("/")) == 4
+        topic_short_name = topic.split("/")[3]
+        with tracer.start_as_current_span(
+            name=f"{topic_short_name} create",
+            attributes={
+                "messaging.system": self._OPEN_TELEMETRY_MESSAGING_SYSTEM,
+                "messaging.destination.name": topic_short_name,
+                "code.function": "publish",
+                "messaging.gcp_pubsub.message.ordering_key": ordering_key,
+                "messaging.operation": "create",
+                "gcp.project_id": topic.split("/")[1],
+                "messaging.message.body.size": sys.getsizeof(
+                    self._message.data
+                ),  # sys.getsizeof() used since the attribute expects size of message body in bytes
+            },
+            kind=trace.SpanKind.PRODUCER,
+            end_on_exit=False,
+        ) as create_span:
+            create_span.add_event(
+                name=self._PUBLISH_START_EVENT,
+                attributes={
+                    "timestamp": str(datetime.now()),
+                },
+            )
+            self._create_span = create_span
+            TraceContextTextMapPropagator().inject(
+                carrier=self._message,
+                setter=OpenTelemetryContextSetter(),
+            )
+
+    def end_create_span(self, exc: Optional[BaseException] = None) -> None:
+        assert self._create_span is not None
+        if exc:
+            self._create_span.record_exception(exception=exc)
+            self._create_span.set_status(
+                trace.Status(status_code=trace.StatusCode.ERROR)
+            )
+        self._create_span.end()
+
+    def start_publisher_flow_control_span(self) -> None:
+        tracer = trace.get_tracer(self._OPEN_TELEMETRY_TRACER_NAME)
+        assert self._create_span is not None
+        with tracer.start_as_current_span(
+            name=self._PUBLISH_FLOW_CONTROL,
+            kind=trace.SpanKind.INTERNAL,
+            context=set_span_in_context(self._create_span),
+            end_on_exit=False,
+        ) as flow_control_span:
+            self._flow_control_span = flow_control_span
+
+    def end_publisher_flow_control_span(
+        self, exc: Optional[BaseException] = None
+    ) -> None:
+        assert self._flow_control_span is not None
+        if exc:
+            self._flow_control_span.record_exception(exception=exc)
+            self._flow_control_span.set_status(
+                trace.Status(status_code=trace.StatusCode.ERROR)
+            )
+        self._flow_control_span.end()
+
+    def start_publisher_batching_span(self) -> None:
+        assert self._create_span is not None
+        tracer = trace.get_tracer(self._OPEN_TELEMETRY_TRACER_NAME)
+        with tracer.start_as_current_span(
+            name=self._OPEN_TELEMETRY_PUBLISHER_BATCHING,
+            kind=trace.SpanKind.INTERNAL,
+            context=set_span_in_context(self._create_span),
+            end_on_exit=False,
+        ) as batching_span:
+            self._batching_span = batching_span
+
+    def end_publisher_batching_span(self, exc: Optional[BaseException] = None) -> None:
+        assert self._batching_span is not None
+        if exc:
+            self._batching_span.record_exception(exception=exc)
+            self._batching_span.set_status(
+                trace.Status(status_code=trace.StatusCode.ERROR)
+            )
+        self._batching_span.end()

google/cloud/pubsub_v1/publisher/_batch/base.py

@@ -19,6 +19,10 @@
 import typing
 from typing import Optional, Sequence
 
+from google.cloud.pubsub_v1.open_telemetry.publish_message_wrapper import (
+    PublishMessageWrapper,
+)
+
 
 if typing.TYPE_CHECKING:  # pragma: NO COVER
     from google.cloud import pubsub_v1
@@ -54,7 +58,7 @@ class Batch(metaclass=abc.ABCMeta):
 
     def __len__(self):
         """Return the number of messages currently in the batch."""
-        return len(self.messages)
+        return len(self.message_wrappers)
 
     @staticmethod
     @abc.abstractmethod
@@ -68,7 +72,7 @@ def make_lock():  # pragma: NO COVER
 
     @property
     @abc.abstractmethod
-    def messages(self) -> Sequence["gapic_types.PubsubMessage"]:  # pragma: NO COVER
+    def message_wrappers(self) -> Sequence[PublishMessageWrapper]:  # pragma: NO COVER
         """Return the messages currently in the batch.
 
         Returns: