Logging: Defensively access provider resource

Now service name is extracted from the provider defensively and lazily.
This accounts for an SDK that does not provide access to "resource" via
TracerProviders and for lazy initialization of TracerProviders.

Fixes open-telemetry#810

Author: owais

CHANGELOG.md

@@ -7,6 +7,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased](https://github.com/open-telemetry/opentelemetry-python/compare/v1.9.1-0.28b1...HEAD)
 
+### Fixed
+
+- `opentelemetry-instrumentation-logging` retrieves service name defensively.
+  ([#890](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/890))
+
 ## [1.9.1-0.28b1](https://github.com/open-telemetry/opentelemetry-python/releases/tag/v1.9.1-0.28b1) - 2022-01-29
 
 

instrumentation/opentelemetry-instrumentation-logging/src/opentelemetry/instrumentation/logging/__init__.py

@@ -16,7 +16,7 @@
 
 import logging  # pylint: disable=import-self
 from os import environ
-from typing import Collection
+from typing import Collection, Optional
 
 from opentelemetry.instrumentation.instrumentor import BaseInstrumentor
 from opentelemetry.instrumentation.logging.constants import (
@@ -76,20 +76,26 @@ def instrumentation_dependencies(self) -> Collection[str]:
         return _instruments
 
     def _instrument(self, **kwargs):
-        service_name = ""
-        provider = kwargs.get("tracer_provider", None) or get_tracer_provider()
-        resource = provider.resource if provider else None
-        if resource:
-            service_name = resource.attributes.get("service.name")
 
         old_factory = logging.getLogRecordFactory()
         LoggingInstrumentor._old_factory = old_factory
 
+        service_name = None
         def record_factory(*args, **kwargs):
             record = old_factory(*args, **kwargs)
 
             record.otelSpanID = "0"
             record.otelTraceID = "0"
+
+            nonlocal service_name
+            if service_name is None:
+                provider = kwargs.get("tracer_provider", None) or get_tracer_provider()
+                resource = getattr(provider, "resource", None)
+                if resource:
+                    service_name = resource.attributes.get("service.name") or ""
+                else:
+                    service_name = ""
+
             record.otelServiceName = service_name
 
             span = get_current_span()
@@ -100,6 +106,7 @@ def record_factory(*args, **kwargs):
                     record.otelTraceID = format(ctx.trace_id, "032x")
             return record
 
+
         logging.setLogRecordFactory(record_factory)
 
         set_logging_format = kwargs.get(