LogRecord Resource Serialization

Currently, the `LogRecord.to_json`
method serializes the resource object
using `repr` of its attributes. This
differs from how the serialization
process is handled in `ReadableSpan.to_json`
and `MetricsData.to_json`, which utilize the
`Resource.to_json` functionality directly.
Using `repr` does not produce a json-parseable
output and doesn't follow the same depth of
serialization as the other two signal types.
Therefore, this change carries over the
serialization process from the spans and
metrics signal types to the logs type.

Fixes open-telemetry#3345

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

@@ -211,9 +211,9 @@ def to_json(self, indent=4) -> str:
                 if self.span_id is not None
                 else "",
                 "trace_flags": self.trace_flags,
-                "resource": repr(self.resource.attributes)
+                "resource": json.loads(self.resource.to_json())
                 if self.resource
-                else "",
+                else None,
             },
             indent=indent,
         )

opentelemetry-sdk/tests/logs/test_log_record.py

@@ -31,7 +31,7 @@ def test_log_record_to_json(self):
                 "trace_id": "",
                 "span_id": "",
                 "trace_flags": None,
-                "resource": "",
+                "resource": None,
             },
             indent=4,
         )