adding support for Jaeger propagator

opentelemetry-sdk/src/opentelemetry/sdk/trace/propagation/jaeger_format.py

@@ -0,0 +1,68 @@
+# Copyright The OpenTelemetry Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import typing
+
+import opentelemetry.trace as trace
+from opentelemetry.context import Context
+from opentelemetry.trace.propagation.textmap import (
+    Getter,
+    Setter,
+    TextMapPropagator,
+    TextMapPropagatorT,
+)
+from opentelemetry import baggage
+
+class JaegerFormat(TextMapPropagator):
+    """Propagator for the Jaeger format.
+
+    See: https://www.jaegertracing.io/docs/1.19/client-libraries/#propagation-format
+    """
+
+    TRACE_ID_KEY = 'uber-trace-id'
+    def inject(
+        self,
+        set_in_carrier: Setter[TextMapPropagatorT],
+        carrier: TextMapPropagatorT,
+        context: typing.Optional[Context] = None,
+    ) -> None:
+        span = trace.get_current_span(context=context)
+        span_context = span.get_context()
+        if span_context == trace.INVALID_SPAN_CONTEXT:
+            return
+
+        # set span identity
+        span_parent_id = getattr(span, "parent", 0)
+        set_in_carrier(
+            carrier, self.TRACE_ID_KEY, _format_trace_id(span_context.trace_id, span_context.span_id, span_parent_id, span_context.trace_flags)
+        )
+
+        # set span baggage, if any
+        baggage_entries = baggage.get_all(context=context)
+        if not baggage_entries:
+            return
+
+        for key, value in baggage_entries.items():
+            baggage_key = 'uberctx-{}'.format(key)
+            set_in_carrier(
+              carrier, baggage_key, value
+            )
+
+
+def _format_trace_id(trace_id, span_id, parent_span_id, flags):
+    return '{:032x}:{:016x}:{:016x}:{:02x}'.format(trace_id, span_id, parent_span_id, flags)
+
+
+
+