fix: suppression propagation in kafka

Signed-off-by: Varsha GS <[email protected]>

Author: GSVarsha

src/instana/propagators/kafka_propagator.py

@@ -1,15 +1,12 @@
 # (c) Copyright IBM Corp. 2025
-from typing import TYPE_CHECKING, Any, Dict, Optional
+from typing import Any, Dict, Optional
 
 from opentelemetry.trace.span import format_span_id
 
 from instana.log import logger
 from instana.propagators.base_propagator import BasePropagator, CarrierT
 from instana.util.ids import hex_id_limited
-
-if TYPE_CHECKING:
-    from instana.span_context import SpanContext
-
+from instana.span_context import SpanContext
 
 class KafkaPropagator(BasePropagator):
     """
@@ -53,7 +50,7 @@ def extract_carrier_headers(self, carrier: CarrierT) -> Dict[str, Any]:
 
     def extract(
         self, carrier: CarrierT, disable_w3c_trace_context: bool = False
-    ) -> Optional["SpanContext"]:
+    ) -> Optional[SpanContext]:
         """
         This method overrides one of the Base classes as with the introduction
         of W3C trace context for the Kafka requests more extracting steps and
@@ -64,7 +61,7 @@ def extract(
             disable_w3c_trace_context (bool): A flag to disable the W3C trace context.
 
         Returns:
-            Optional["SpanContext"]: The extracted span context or None.
+            Optional[SpanContext]: The extracted span context or None.
         """
         try:
             headers = self.extract_carrier_headers(carrier=carrier)
@@ -79,7 +76,7 @@ def extract(
     # Assisted by watsonx Code Assistant
     def inject(
         self,
-        span_context: "SpanContext",
+        span_context: SpanContext,
         carrier: CarrierT,
         disable_w3c_trace_context: bool = True,
     ) -> None:
@@ -103,7 +100,26 @@ def inject(
             # Suppression `level` made in the child context or in the parent context
             # has priority over any non-suppressed `level` setting
             suppression_level = int(self.extract_instana_headers(dictionary_carrier)[2])
-            span_context.level = min(suppression_level, span_context.level)
+            new_level = min(suppression_level, span_context.level)
+
+            if new_level != span_context.level:
+                # Create a new span context with the updated level
+                span_context = SpanContext(
+                    trace_id=span_context.trace_id,
+                    span_id=span_context.span_id,
+                    is_remote=span_context.is_remote,
+                    trace_flags=span_context.trace_flags,
+                    trace_state=span_context.trace_state,
+                    level=new_level,
+                    synthetic=span_context.synthetic,
+                    trace_parent=span_context.trace_parent,
+                    instana_ancestor=span_context.instana_ancestor,
+                    long_trace_id=span_context.long_trace_id,
+                    correlation_type=span_context.correlation_type,
+                    correlation_id=span_context.correlation_id,
+                    traceparent=span_context.traceparent,
+                    tracestate=span_context.tracestate
+                )
 
         def inject_key_value(carrier, key, value):
             if isinstance(carrier, list):
@@ -119,9 +135,9 @@ def inject_key_value(carrier, key, value):
             inject_key_value(
                 carrier,
                 self.KAFKA_HEADER_KEY_L_S,
-                str(suppression_level).encode("utf-8"),
+                str(span_context.level).encode("utf-8"),
             )
-            if suppression_level == 1:
+            if span_context.level == 1:
                 inject_key_value(
                     carrier,
                     self.KAFKA_HEADER_KEY_T,