fix(logging): remove log correlation attributes from ddtrace loggers (#14979)

## Description

Fixes ddtrace internal logging errors when trace-log correlation is
disabled programmatically.

## Problem

ddtrace internal logs were expecting correlation attributes
(`dd.service`, etc.) even when log injection was disabled, causing
`ValueError: Formatting field not found in record` errors.

## Solution

Removed set_log_formatting to prevent mismatches between expected and
actual log record attributes. When log correlation is disabled but
DD_LOG_FORMAT is set, internal ddtrace logs can raise a ValueError. This
also prevents issues when user configured log formatters override log
formatters set by ddtrace. Since span start and finish now emit debug
logs, including trace attributes in all ddtrace log records is no longer
necessary.

## Testing

Verified ddtrace internal logs work correctly with correlation disabled.

## Risks

None - fixes existing bug.

(cherry picked from commit b433817)

Author: mabdinur

ddtrace/_logger.py

@@ -110,14 +110,6 @@ 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

@@ -5,7 +5,6 @@
 
 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
@@ -100,13 +99,6 @@ 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

@@ -0,0 +1,5 @@
+---
+fixes:
+  - |
+    logging: Fixed ddtrace internal logging when trace-log correlation is disabled. 
+    Prevents ``ValueError: Formatting field not found in record: 'dd.service'``.

tests/integration/test_integration.py

@@ -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]" in err
-    ), "stderr should 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]" not in err
+    ), "stderr should not 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 (