Zipkin exporter to get service_name from span instead of global tracer_provider (#1696)

Author: lzchen

CHANGELOG.md

@@ -54,6 +54,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   ([#1671](https://github.com/open-telemetry/opentelemetry-python/pull/1671))
 - Initial documentation for environment variables
   ([#1680](https://github.com/open-telemetry/opentelemetry-python/pull/1680))
+- Change Zipkin exporter to obtain service.name from span
+  ([#1696](https://github.com/open-telemetry/opentelemetry-python/pull/1696))
 
 ### Removed
 - Removed unused `get_hexadecimal_trace_id` and `get_hexadecimal_span_id` methods.

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

@@ -71,14 +71,19 @@
 
 import requests
 
-from opentelemetry.exporter.zipkin.encoder import Encoder, Protocol
+from opentelemetry.exporter.zipkin.encoder import (
+    DEFAULT_MAX_TAG_VALUE_LENGTH,
+    Encoder,
+    Protocol,
+)
 from opentelemetry.exporter.zipkin.encoder.v1.json import JsonV1Encoder
 from opentelemetry.exporter.zipkin.encoder.v2.json import JsonV2Encoder
 from opentelemetry.exporter.zipkin.encoder.v2.protobuf import ProtobufEncoder
 from opentelemetry.exporter.zipkin.node_endpoint import IpInput, NodeEndpoint
 from opentelemetry.sdk.environment_variables import (
     OTEL_EXPORTER_ZIPKIN_ENDPOINT,
 )
+from opentelemetry.sdk.resources import SERVICE_NAME
 from opentelemetry.sdk.trace.export import SpanExporter, SpanExportResult
 from opentelemetry.trace import Span
 
@@ -116,6 +121,15 @@ def __init__(
             self.encoder = ProtobufEncoder(max_tag_value_length)
 
     def export(self, spans: Sequence[Span]) -> SpanExportResult:
+        # Populate service_name from first span
+        # We restrict any SpanProcessor to be only associated with a single
+        # TracerProvider, so it is safe to assume that all Spans in a single
+        # batch all originate from one TracerProvider (and in turn have all
+        # the same service.name)
+        if spans:
+            service_name = spans[0].resource.attributes.get(SERVICE_NAME)
+            if service_name:
+                self.local_node.service_name = service_name
         result = requests.post(
             url=self.endpoint,
             data=self.encoder.serialize(spans, self.local_node),

exporter/opentelemetry-exporter-zipkin/src/opentelemetry/exporter/zipkin/encoder/__init__.py

@@ -144,20 +144,26 @@ def _extract_tags_from_dict(
                 logger.warning("Could not serialize tag %s", attribute_key)
                 continue
 
-            if self.max_tag_value_length > 0:
+            if (
+                self.max_tag_value_length is not None
+                and self.max_tag_value_length > 0
+            ):
                 value = value[: self.max_tag_value_length]
             tags[attribute_key] = value
         return tags
 
     def _extract_tag_value_string_from_sequence(self, sequence: Sequence):
-        if self.max_tag_value_length == 1:
+        if self.max_tag_value_length and self.max_tag_value_length == 1:
             return None
 
         tag_value_elements = []
         running_string_length = (
             2  # accounts for array brackets in output string
         )
-        defined_max_tag_value_length = self.max_tag_value_length > 0
+        defined_max_tag_value_length = (
+            self.max_tag_value_length is not None
+            and self.max_tag_value_length > 0
+        )
 
         for element in sequence:
             if isinstance(element, bool):
@@ -214,7 +220,11 @@ def _extract_annotations_from_events(
         for event in events:
             attrs = {}
             for key, value in event.attributes.items():
-                if isinstance(value, str) and self.max_tag_value_length > 0:
+                if (
+                    isinstance(value, str)
+                    and self.max_tag_value_length is not None
+                    and self.max_tag_value_length > 0
+                ):
                     value = value[: self.max_tag_value_length]
                 attrs[key] = value
 

exporter/opentelemetry-exporter-zipkin/tests/test_zipkin_exporter.py

@@ -26,7 +26,7 @@
     OTEL_EXPORTER_ZIPKIN_ENDPOINT,
 )
 from opentelemetry.sdk.resources import SERVICE_NAME, Resource
-from opentelemetry.sdk.trace import TracerProvider
+from opentelemetry.sdk.trace import TracerProvider, _Span
 from opentelemetry.sdk.trace.export import SpanExportResult
 
 TEST_SERVICE_NAME = "test_service"
@@ -122,13 +122,37 @@ def test_constructor_all_params_and_env_vars(self):
         self.assertEqual(exporter.local_node.port, local_node_port)
 
     @patch("requests.post")
-    def test_invalid_response(self, mock_post):
+    def test_export_success(self, mock_post):
+        mock_post.return_value = MockResponse(200)
+        spans = []
+        exporter = ZipkinExporter(Protocol.V2_PROTOBUF)
+        status = exporter.export(spans)
+        self.assertEqual(SpanExportResult.SUCCESS, status)
+
+    @patch("requests.post")
+    def test_export_invalid_response(self, mock_post):
         mock_post.return_value = MockResponse(404)
         spans = []
         exporter = ZipkinExporter(Protocol.V2_PROTOBUF)
         status = exporter.export(spans)
         self.assertEqual(SpanExportResult.FAILURE, status)
 
+    @patch("requests.post")
+    def test_export_span_service_name(self, mock_post):
+        mock_post.return_value = MockResponse(200)
+        resource = Resource.create({SERVICE_NAME: "test"})
+        context = trace.SpanContext(
+            trace_id=0x000000000000000000000000DEADBEEF,
+            span_id=0x00000000DEADBEF0,
+            is_remote=False,
+        )
+        span = _Span("test_span", context=context, resource=resource)
+        span.start()
+        span.end()
+        exporter = ZipkinExporter(Protocol.V2_PROTOBUF)
+        exporter.export([span])
+        self.assertEqual(exporter.local_node.service_name, "test")
+
 
 class TestZipkinNodeEndpoint(unittest.TestCase):
     def test_constructor_default(self):