changing the getter function with getter objects in instrumentation

instrumentation/opentelemetry-instrumentation-django/src/opentelemetry/instrumentation/django/middleware.py

@@ -21,7 +21,7 @@
 from opentelemetry.instrumentation.wsgi import (
     add_response_attributes,
     collect_request_attributes,
-    get_header_from_environ,
+    getter,
 )
 from opentelemetry.propagators import extract
 from opentelemetry.trace import SpanKind, get_tracer
@@ -98,7 +98,7 @@ def process_request(self, request):
 
         environ = request.META
 
-        token = attach(extract(get_header_from_environ, environ))
+        token = attach(extract(getter, environ))
 
         tracer = get_tracer(__name__, __version__)
 

instrumentation/opentelemetry-instrumentation-falcon/src/opentelemetry/instrumentation/falcon/__init__.py

@@ -114,9 +114,7 @@ def __call__(self, env, start_response):
 
         start_time = time_ns()
 
-        token = context.attach(
-            propagators.extract(otel_wsgi.get_header_from_environ, env)
-        )
+        token = context.attach(propagators.extract(otel_wsgi.getter, env))
         attributes = otel_wsgi.collect_request_attributes(env)
         span = self._tracer.start_span(
             otel_wsgi.get_default_span_name(env),

instrumentation/opentelemetry-instrumentation-flask/src/opentelemetry/instrumentation/flask/__init__.py

@@ -113,9 +113,7 @@ def _before_request():
     span_name = flask.request.endpoint or otel_wsgi.get_default_span_name(
         environ
     )
-    token = context.attach(
-        propagators.extract(otel_wsgi.get_header_from_environ, environ)
-    )
+    token = context.attach(propagators.extract(otel_wsgi.getter, environ))
 
     tracer = trace.get_tracer(__name__, __version__)
 

instrumentation/opentelemetry-instrumentation-pyramid/src/opentelemetry/instrumentation/pyramid/callbacks.py

@@ -69,9 +69,7 @@ def _before_traversal(event):
 
     start_time = environ.get(_ENVIRON_STARTTIME_KEY)
 
-    token = context.attach(
-        propagators.extract(otel_wsgi.get_header_from_environ, environ)
-    )
+    token = context.attach(propagators.extract(otel_wsgi.getter, environ))
     tracer = trace.get_tracer(__name__, __version__)
 
     if request.matched_route:

opentelemetry-api/src/opentelemetry/trace/propagation/textmap.py

@@ -14,6 +14,7 @@
 
 import abc
 import typing
+from typing import Optional
 
 from opentelemetry.context.context import Context
 
@@ -22,6 +23,20 @@
 Setter = typing.Callable[[TextMapPropagatorT, str, str], None]
 
 
+def default_get(carrier: TextMapPropagatorT, key: str) -> typing.List[str]:
+    return [carrier.get(key)] if carrier.get(key) else []
+
+
+def default_keys(carrier: TextMapPropagatorT) -> typing.List[str]:
+    return list(carrier.keys())
+
+
+GetterGetFunction = typing.Callable[
+    [TextMapPropagatorT, str], typing.List[str]
+]
+GetterKeysFunction = typing.Callable[[TextMapPropagatorT], typing.List[str]]
+
+
 class Getter:
     """This class implements a Getter that enables extracting propagated
     fields from a carrier
@@ -30,10 +45,8 @@ class Getter:
 
     def __init__(
         self,
-        get=lambda carrier, key: [carrier.get(key)]
-        if carrier.get(key)
-        else [],
-        keys=lambda carrier: list(carrier.keys()),
+        get: GetterGetFunction[TextMapPropagatorT] = default_get,
+        keys: GetterKeysFunction[TextMapPropagatorT] = default_keys,
     ):
         self._get = get
         self._keys = keys