fix: Ensure extraction of headers from dictionary

Signed-off-by: Ferenc Géczi <ferenc.geczi@ibm.com>

src/instana/propagators/base_propagator.py

@@ -66,7 +66,7 @@ def __init__(self):
         self._ts = Tracestate()
 
     @staticmethod
-    def _extract_headers_dict(carrier):
+    def extract_headers_dict(carrier):
         """
         This method converts the incoming carrier into a dict
         :param carrier:
@@ -278,7 +278,7 @@ def extract(self, carrier, disable_w3c_trace_context=False):
         """
         try:
             traceparent, tracestate = [None] * 2
-            headers = self._extract_headers_dict(carrier=carrier)
+            headers = self.extract_headers_dict(carrier=carrier)
             if headers is None:
                 return None
             headers = {k.lower(): v for k, v in headers.items()}

src/instana/propagators/http_propagator.py

@@ -20,10 +20,13 @@ def __init__(self):
     def inject(self, span_context, carrier, disable_w3c_trace_context=False):
         trace_id = span_context.trace_id
         span_id = span_context.span_id
-        # Suppression `level` made in the child context or in the parent context
-        # has priority over any non-suppressed `level` setting
-        child_level = int(self.extract_instana_headers(carrier)[2] or "1")
-        span_context.level = min(child_level, span_context.level)
+        dictionary_carrier = self.extract_headers_dict(carrier)
+        if dictionary_carrier:
+            # Suppression `level` made in the child context or in the parent context
+            # has priority over any non-suppressed `level` setting
+            child_level = int(self.extract_instana_headers(dictionary_carrier)[2] or "1")
+            span_context.level = min(child_level, span_context.level)
+
         serializable_level = str(span_context.level)
 
         if disable_w3c_trace_context: