Make propagators conform to spec (#488)

* Make propagators conform to spec

* do not modify / set an invalid span in the passed context in case
  a propagator did not manage to extract
* in case no context is passed to propagator.extract assume the root
  context as default so that a new trace is started instead of continung
  the current active trace in case extraction fails
* fix also ot-trace propagator which compared int with str trace/span ids
  when checking for validity in extract

Author: mariojonke

Diff for: CHANGELOG.md

@@ -14,6 +14,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   ([#504](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/504))
 - `opentelemetry-instrumentation-asgi` Fix instrumentation default span name.
   ([#418](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/418))
+- Propagators use the root context as default for `extract` and do not modify
+  the context if extracting from carrier does not work.
+  ([#488](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/488))
 
 ### Added
 - `opentelemetry-instrumentation-botocore` now supports

Diff for: exporter/opentelemetry-exporter-datadog/src/opentelemetry/exporter/datadog/propagator.py

@@ -42,6 +42,9 @@ def extract(
         context: typing.Optional[Context] = None,
         getter: Getter = default_getter,
     ) -> Context:
+        if context is None:
+            context = Context()
+
         trace_id = extract_first_element(
             getter.get(carrier, self.TRACE_ID_KEY)
         )
@@ -64,7 +67,7 @@ def extract(
             trace_flags = trace.TraceFlags(trace.TraceFlags.SAMPLED)
 
         if trace_id is None or span_id is None:
-            return set_span_in_context(trace.INVALID_SPAN, context)
+            return context
 
         trace_state = []
         if origin is not None:

Diff for: exporter/opentelemetry-exporter-datadog/tests/test_datadog_format.py

@@ -16,6 +16,7 @@
 from unittest.mock import Mock, patch
 
 from opentelemetry import trace as trace_api
+from opentelemetry.context import Context
 from opentelemetry.exporter.datadog import constants, propagator
 from opentelemetry.sdk import trace
 from opentelemetry.sdk.trace.id_generator import RandomIdGenerator
@@ -36,42 +37,58 @@ def setUpClass(cls):
         )
         cls.serialized_origin = "origin-service"
 
-    def test_malformed_headers(self):
+    def test_extract_malformed_headers_to_explicit_ctx(self):
         """Test with no Datadog headers"""
+        orig_ctx = Context({"k1": "v1"})
         malformed_trace_id_key = FORMAT.TRACE_ID_KEY + "-x"
         malformed_parent_id_key = FORMAT.PARENT_ID_KEY + "-x"
-        context = get_current_span(
-            FORMAT.extract(
-                {
-                    malformed_trace_id_key: self.serialized_trace_id,
-                    malformed_parent_id_key: self.serialized_parent_id,
-                },
-            )
-        ).get_span_context()
+        context = FORMAT.extract(
+            {
+                malformed_trace_id_key: self.serialized_trace_id,
+                malformed_parent_id_key: self.serialized_parent_id,
+            },
+            orig_ctx,
+        )
+        self.assertDictEqual(orig_ctx, context)
 
-        self.assertNotEqual(context.trace_id, int(self.serialized_trace_id))
-        self.assertNotEqual(context.span_id, int(self.serialized_parent_id))
-        self.assertFalse(context.is_remote)
+    def test_extract_malformed_headers_to_implicit_ctx(self):
+        malformed_trace_id_key = FORMAT.TRACE_ID_KEY + "-x"
+        malformed_parent_id_key = FORMAT.PARENT_ID_KEY + "-x"
+        context = FORMAT.extract(
+            {
+                malformed_trace_id_key: self.serialized_trace_id,
+                malformed_parent_id_key: self.serialized_parent_id,
+            }
+        )
+        self.assertDictEqual(Context(), context)
 
-    def test_missing_trace_id(self):
+    def test_extract_missing_trace_id_to_explicit_ctx(self):
         """If a trace id is missing, populate an invalid trace id."""
-        carrier = {
-            FORMAT.PARENT_ID_KEY: self.serialized_parent_id,
-        }
+        orig_ctx = Context({"k1": "v1"})
+        carrier = {FORMAT.PARENT_ID_KEY: self.serialized_parent_id}
+
+        ctx = FORMAT.extract(carrier, orig_ctx)
+        self.assertDictEqual(orig_ctx, ctx)
+
+    def test_extract_missing_trace_id_to_implicit_ctx(self):
+        carrier = {FORMAT.PARENT_ID_KEY: self.serialized_parent_id}
 
         ctx = FORMAT.extract(carrier)
-        span_context = get_current_span(ctx).get_span_context()
-        self.assertEqual(span_context.trace_id, trace_api.INVALID_TRACE_ID)
+        self.assertDictEqual(Context(), ctx)
 
-    def test_missing_parent_id(self):
+    def test_extract_missing_parent_id_to_explicit_ctx(self):
         """If a parent id is missing, populate an invalid trace id."""
-        carrier = {
-            FORMAT.TRACE_ID_KEY: self.serialized_trace_id,
-        }
+        orig_ctx = Context({"k1": "v1"})
+        carrier = {FORMAT.TRACE_ID_KEY: self.serialized_trace_id}
+
+        ctx = FORMAT.extract(carrier, orig_ctx)
+        self.assertDictEqual(orig_ctx, ctx)
+
+    def test_extract_missing_parent_id_to_implicit_ctx(self):
+        carrier = {FORMAT.TRACE_ID_KEY: self.serialized_trace_id}
 
         ctx = FORMAT.extract(carrier)
-        span_context = get_current_span(ctx).get_span_context()
-        self.assertEqual(span_context.span_id, trace_api.INVALID_SPAN_ID)
+        self.assertDictEqual(Context(), ctx)
 
     def test_context_propagation(self):
         """Test the propagation of Datadog headers."""

Diff for: propagator/opentelemetry-propagator-ot-trace/src/opentelemetry/propagators/ot_trace/__init__.py

@@ -55,13 +55,19 @@ def extract(
         context: Optional[Context] = None,
         getter: Getter = default_getter,
     ) -> Context:
+        if context is None:
+            context = Context()
 
-        traceid = _extract_first_element(
-            getter.get(carrier, OT_TRACE_ID_HEADER), INVALID_TRACE_ID
+        traceid = _extract_identifier(
+            getter.get(carrier, OT_TRACE_ID_HEADER),
+            _valid_extract_traceid,
+            INVALID_TRACE_ID,
         )
 
-        spanid = _extract_first_element(
-            getter.get(carrier, OT_SPAN_ID_HEADER), INVALID_SPAN_ID
+        spanid = _extract_identifier(
+            getter.get(carrier, OT_SPAN_ID_HEADER),
+            _valid_extract_spanid,
+            INVALID_SPAN_ID,
         )
 
         sampled = _extract_first_element(
@@ -73,17 +79,12 @@ def extract(
         else:
             traceflags = TraceFlags.DEFAULT
 
-        if (
-            traceid != INVALID_TRACE_ID
-            and _valid_extract_traceid.fullmatch(traceid) is not None
-            and spanid != INVALID_SPAN_ID
-            and _valid_extract_spanid.fullmatch(spanid) is not None
-        ):
+        if traceid != INVALID_TRACE_ID and spanid != INVALID_SPAN_ID:
             context = set_span_in_context(
                 NonRecordingSpan(
                     SpanContext(
-                        trace_id=int(traceid, 16),
-                        span_id=int(spanid, 16),
+                        trace_id=traceid,
+                        span_id=spanid,
                         is_remote=True,
                         trace_flags=TraceFlags(traceflags),
                     )
@@ -172,3 +173,16 @@ def _extract_first_element(
     if items is None:
         return default
     return next(iter(items), None)
+
+
+def _extract_identifier(
+    items: Iterable[CarrierT], validator_pattern, default: int
+) -> int:
+    header = _extract_first_element(items)
+    if header is None or validator_pattern.fullmatch(header) is None:
+        return default
+
+    try:
+        return int(header, 16)
+    except ValueError:
+        return default

Diff for: propagator/opentelemetry-propagator-ot-trace/tests/test_ot_trace_propagator.py

@@ -15,6 +15,7 @@
 from unittest import TestCase
 
 from opentelemetry.baggage import get_all, set_baggage
+from opentelemetry.context import Context
 from opentelemetry.propagators.ot_trace import (
     OT_BAGGAGE_PREFIX,
     OT_SAMPLED_HEADER,
@@ -24,8 +25,6 @@
 )
 from opentelemetry.sdk.trace import _Span
 from opentelemetry.trace import (
-    INVALID_SPAN_CONTEXT,
-    INVALID_SPAN_ID,
     INVALID_TRACE_ID,
     SpanContext,
     TraceFlags,
@@ -275,65 +274,44 @@ def test_extract_trace_id_span_id_sampled_false(self):
             get_current_span().get_span_context().trace_flags, TraceFlags
         )
 
-    def test_extract_malformed_trace_id(self):
-        """Test extraction with malformed trace_id"""
-
-        span_context = get_current_span(
-            self.ot_trace_propagator.extract(
-                {
-                    OT_TRACE_ID_HEADER: "abc123!",
-                    OT_SPAN_ID_HEADER: "e457b5a2e4d86bd1",
-                    OT_SAMPLED_HEADER: "false",
-                },
-            )
-        ).get_span_context()
-
-        self.assertEqual(span_context, INVALID_SPAN_CONTEXT)
-
-    def test_extract_malformed_span_id(self):
-        """Test extraction with malformed span_id"""
-
-        span_context = get_current_span(
-            self.ot_trace_propagator.extract(
-                {
-                    OT_TRACE_ID_HEADER: "64fe8b2a57d3eff7",
-                    OT_SPAN_ID_HEADER: "abc123!",
-                    OT_SAMPLED_HEADER: "false",
-                },
-            )
-        ).get_span_context()
-
-        self.assertEqual(span_context, INVALID_SPAN_CONTEXT)
-
-    def test_extract_invalid_trace_id(self):
-        """Test extraction with invalid trace_id"""
-
-        span_context = get_current_span(
-            self.ot_trace_propagator.extract(
-                {
-                    OT_TRACE_ID_HEADER: INVALID_TRACE_ID,
-                    OT_SPAN_ID_HEADER: "e457b5a2e4d86bd1",
-                    OT_SAMPLED_HEADER: "false",
-                },
-            )
-        ).get_span_context()
-
-        self.assertEqual(span_context, INVALID_SPAN_CONTEXT)
-
-    def test_extract_invalid_span_id(self):
-        """Test extraction with invalid span_id"""
-
-        span_context = get_current_span(
-            self.ot_trace_propagator.extract(
-                {
-                    OT_TRACE_ID_HEADER: "64fe8b2a57d3eff7",
-                    OT_SPAN_ID_HEADER: INVALID_SPAN_ID,
-                    OT_SAMPLED_HEADER: "false",
-                },
-            )
-        ).get_span_context()
-
-        self.assertEqual(span_context, INVALID_SPAN_CONTEXT)
+    def test_extract_invalid_trace_header_to_explict_ctx(self):
+        invalid_headers = [
+            ("abc123!", "e457b5a2e4d86bd1"),  # malformed trace id
+            ("64fe8b2a57d3eff7", "abc123!"),  # malformed span id
+            ("0" * 32, "e457b5a2e4d86bd1"),  # invalid trace id
+            ("64fe8b2a57d3eff7", "0" * 16),  # invalid span id
+        ]
+        for trace_id, span_id in invalid_headers:
+            with self.subTest(trace_id=trace_id, span_id=span_id):
+                orig_ctx = Context({"k1": "v1"})
+
+                ctx = self.ot_trace_propagator.extract(
+                    {
+                        OT_TRACE_ID_HEADER: trace_id,
+                        OT_SPAN_ID_HEADER: span_id,
+                        OT_SAMPLED_HEADER: "false",
+                    },
+                    orig_ctx,
+                )
+                self.assertDictEqual(orig_ctx, ctx)
+
+    def test_extract_invalid_trace_header_to_implicit_ctx(self):
+        invalid_headers = [
+            ("abc123!", "e457b5a2e4d86bd1"),  # malformed trace id
+            ("64fe8b2a57d3eff7", "abc123!"),  # malformed span id
+            ("0" * 32, "e457b5a2e4d86bd1"),  # invalid trace id
+            ("64fe8b2a57d3eff7", "0" * 16),  # invalid span id
+        ]
+        for trace_id, span_id in invalid_headers:
+            with self.subTest(trace_id=trace_id, span_id=span_id):
+                ctx = self.ot_trace_propagator.extract(
+                    {
+                        OT_TRACE_ID_HEADER: trace_id,
+                        OT_SPAN_ID_HEADER: span_id,
+                        OT_SAMPLED_HEADER: "false",
+                    }
+                )
+                self.assertDictEqual(Context(), ctx)
 
     def test_extract_baggage(self):
         """Test baggage extraction"""
@@ -359,11 +337,13 @@ def test_extract_baggage(self):
         self.assertEqual(baggage["abc"], "abc")
         self.assertEqual(baggage["def"], "def")
 
-    def test_extract_empty(self):
-        "Test extraction when no headers are present"
+    def test_extract_empty_to_explicit_ctx(self):
+        """Test extraction when no headers are present"""
+        orig_ctx = Context({"k1": "v1"})
+        ctx = self.ot_trace_propagator.extract({}, orig_ctx)
 
-        span_context = get_current_span(
-            self.ot_trace_propagator.extract({})
-        ).get_span_context()
+        self.assertDictEqual(orig_ctx, ctx)
 
-        self.assertEqual(span_context, INVALID_SPAN_CONTEXT)
+    def test_extract_empty_to_implicit_ctx(self):
+        ctx = self.ot_trace_propagator.extract({})
+        self.assertDictEqual(Context(), ctx)

Diff for: sdk-extension/opentelemetry-sdk-extension-aws/src/opentelemetry/sdk/extension/aws/trace/propagation/aws_xray_format.py

@@ -106,19 +106,18 @@ def extract(
         context: typing.Optional[Context] = None,
         getter: Getter = default_getter,
     ) -> Context:
+        if context is None:
+            context = Context()
+
         trace_header_list = getter.get(carrier, TRACE_HEADER_KEY)
 
         if not trace_header_list or len(trace_header_list) != 1:
-            return trace.set_span_in_context(
-                trace.INVALID_SPAN, context=context
-            )
+            return context
 
         trace_header = trace_header_list[0]
 
         if not trace_header:
-            return trace.set_span_in_context(
-                trace.INVALID_SPAN, context=context
-            )
+            return context
 
         try:
             (
@@ -128,9 +127,7 @@ def extract(
             ) = AwsXRayFormat._extract_span_properties(trace_header)
         except AwsParseTraceHeaderError as err:
             _logger.debug(err.message)
-            return trace.set_span_in_context(
-                trace.INVALID_SPAN, context=context
-            )
+            return context
 
         options = 0
         if sampled:
@@ -148,9 +145,7 @@ def extract(
             _logger.debug(
                 "Invalid Span Extracted. Insertting INVALID span into provided context."
             )
-            return trace.set_span_in_context(
-                trace.INVALID_SPAN, context=context
-            )
+            return context
 
         return trace.set_span_in_context(
             trace.NonRecordingSpan(span_context), context=context