chore(logging): revert remove log correlation attributes from ddtrace loggers (#15027)

Reverts #14979

Author: brettlangdon

ddtrace/_logger.py

@@ -110,6 +110,14 @@ def _add_file_handler(
     return ddtrace_file_handler
 
 
+def set_log_formatting():
+    # type: () -> None
+    """Sets the log format for the ddtrace logger."""
+    ddtrace_logger = logging.getLogger("ddtrace")
+    for handler in ddtrace_logger.handlers:
+        handler.setFormatter(logging.Formatter(DD_LOG_FORMAT))
+
+
 def get_log_injection_state(raw_config: Optional[str]) -> bool:
     """Returns the current log injection state."""
     if raw_config:

ddtrace/contrib/internal/logging/patch.py

@@ -5,6 +5,7 @@
 
 import ddtrace
 from ddtrace import config
+from ddtrace._logger import set_log_formatting
 from ddtrace.contrib.internal.trace_utils import unwrap as _u
 from ddtrace.internal.constants import LOG_ATTR_ENV
 from ddtrace.internal.constants import LOG_ATTR_SERVICE
@@ -99,6 +100,13 @@ def patch():
     _w(logging.Logger, "makeRecord", _w_makeRecord)
     _w(logging.StrFormatStyle, "_format", _w_StrFormatStyle_format)
 
+    if config._logs_injection:
+        # Only set the formatter is DD_LOGS_INJECTION is set to True. We do not want to modify
+        # unstructured logs if a user has not enabled logs injection.
+        # Also, the Datadog log format must be set after the logging module has been patched,
+        # otherwise the formatter will raise an exception.
+        set_log_formatting()
+
 
 def unpatch():
     if getattr(logging, "_datadog_patch", False):

releasenotes/notes/remove-set-log-formatting-a8b9c7d2e1f3g4h5.yaml

@@ -808,8 +808,8 @@ def test_logging_during_tracer_init_succeeds_when_debug_logging_and_logs_injecti
     assert out == b"", "an empty program should generate no logs under ddtrace-run"
 
     assert (
-        b"[dd.service=ddtrace_subprocess_dir dd.env= dd.version= dd.trace_id=0 dd.span_id=0]" not in err
-    ), "stderr should not contain debug output when DD_TRACE_DEBUG is set"
+        b"[dd.service=ddtrace_subprocess_dir dd.env= dd.version= dd.trace_id=0 dd.span_id=0]" in err
+    ), "stderr should contain debug output when DD_TRACE_DEBUG is set"
 
     assert b"KeyError: 'dd.service'" not in err, "stderr should not contain any exception logs"
     assert (