chore(propagation): remove b3 single header

ddtrace/propagation/http.py

@@ -510,7 +510,7 @@ def _extract(headers):
 
 
 class _B3SingleHeader:
-    """Helper class to inject/extract B3 Single Header
+    """Helper class to inject/extract B3
 
     https://github.com/openzipkin/b3-propagation/blob/3e54cda11620a773d53c7f64d2ebb10d3a01794c/README.md#single-header
 

ddtrace/settings/_config.py

@@ -32,7 +32,6 @@
 from ..internal.constants import DEFAULT_SAMPLING_RATE_LIMIT
 from ..internal.constants import DEFAULT_TIMEOUT
 from ..internal.constants import PROPAGATION_STYLE_ALL
-from ..internal.constants import PROPAGATION_STYLE_B3_SINGLE
 from ..internal.logger import get_logger
 from ..internal.schema import DEFAULT_SPAN_SERVICE_NAME
 from ..internal.serverless import in_aws_lambda
@@ -116,7 +115,6 @@ def _parse_propagation_styles(styles_str):
     - "datadog"
     - "b3multi"
     - "b3" (formerly 'b3 single header')
-    - "b3 single header (deprecated for 'b3')"
     - "tracecontext"
     - "baggage"
     - "none"
@@ -142,14 +140,6 @@ def _parse_propagation_styles(styles_str):
     styles = []
     for style in styles_str.split(","):
         style = style.strip().lower()
-        if style == "b3 single header":
-            deprecate(
-                'Using DD_TRACE_PROPAGATION_STYLE="b3 single header" is deprecated',
-                message="Please use 'DD_TRACE_PROPAGATION_STYLE=\"b3\"' instead",
-                removal_version="3.0.0",
-                category=DDTraceDeprecationWarning,
-            )
-            style = PROPAGATION_STYLE_B3_SINGLE
         # None has no propagator so we pull it out
         if not style or style == _PROPAGATION_STYLE_NONE:
             continue

docs/configuration.rst

@@ -278,7 +278,7 @@ Traces
 
          Overridden by ``DD_TRACE_PROPAGATION_STYLE_INJECT`` for injection.
 
-         The supported values are ``datadog``, ``b3multi``, and ``b3 single header``, ``tracecontext``, and ``none``.
+         The supported values are ``datadog``, ``b3multi``, ``tracecontext``, and ``none``.
 
          When checking inbound request headers we will take the first valid trace context in the order provided.
          When ``none`` is the only propagator listed, propagation is disabled.
@@ -357,7 +357,7 @@ Trace Context propagation
 
          Overrides ``DD_TRACE_PROPAGATION_STYLE`` for extraction propagation style.
 
-         The supported values are ``datadog``, ``b3multi``, and ``b3 single header``, ``tracecontext``, and ``none``.
+         The supported values are ``datadog``, ``b3multi``, ``b3``, ``tracecontext``, and ``none``.
 
          When checking inbound request headers we will take the first valid trace context in the order provided.
          When ``none`` is the only propagator listed, extraction is disabled.
@@ -397,7 +397,7 @@ Trace Context propagation
 
          Overrides ``DD_TRACE_PROPAGATION_STYLE`` for injection propagation style.
 
-         The supported values are ``datadog``, ``b3multi``, and ``b3 single header``, ``tracecontext``, and ``none``.
+         The supported values are ``datadog``, ``b3multi``,``b3``, ``tracecontext``, and ``none``.
 
          All provided styles are injected into the headers of outbound requests.
          When ``none`` is the only propagator listed, injection is disabled.

releasenotes/notes/remove-b3-single--4c16c32466c69709.yaml

@@ -0,0 +1,4 @@
+---
+upgrade:
+  - |
+    propagation: Setting ``DD_TRACE_PROPAGATION_STYLE`` to ``b3 single header`` is no longer supported. Use ``b3`` instead.

tests/tracer/test_global_config.py

@@ -1,12 +1,10 @@
-import os
 from unittest import TestCase
 
 import mock
 import pytest
 
 from ddtrace import config as global_config
 from ddtrace.settings import Config
-from ddtrace.settings._config import _parse_propagation_styles
 
 from ..utils import DummyTracer
 from ..utils import override_env
@@ -282,10 +280,3 @@ def test_dd_service_mapping(self):
         with override_env(dict(DD_SERVICE_MAPPING="foobar:bar,snafu:foo")):
             c = Config()
             assert c.service_mapping == {"foobar": "bar", "snafu": "foo"}
-
-    def test_parse_propagation_styles_b3_deprecation(capsys):
-        with pytest.warns(
-            DeprecationWarning, match='Using DD_TRACE_PROPAGATION_STYLE="b3 single header" is deprecated'
-        ), override_env(dict(DD_TRACE_PROPAGATION_STYLE="b3 single header")):
-            style = _parse_propagation_styles(os.environ["DD_TRACE_PROPAGATION_STYLE"])
-            assert style == ["b3"]

tests/tracer/test_propagation.py

@@ -1821,7 +1821,7 @@ def test_extract_tracecontext(headers, expected_context):
             "dd_origin": None,
         },
     ),
-    # B3 single header
+    # B3
     (
         "valid_b3_single_header_simple",
         [PROPAGATION_STYLE_B3_SINGLE],
@@ -2639,7 +2639,7 @@ def test_DD_TRACE_PROPAGATION_STYLE_EXTRACT_overrides_DD_TRACE_PROPAGATION_STYLE
         ),
     ),
     # The trace_id from Datadog context will not align with the tracecontext primary context
-    # therefore we get a span link. B3 single headers are invalid so we won't see a trace of them.
+    # therefore we get a span link. B3 is invalid so we won't see a trace of them.
     # The b3 multi headers are missing a span_id, so we will skip creating a span link for it.
     (
         "all_headers_all_styles_do_not_create_span_link_for_context_w_out_span_id",
@@ -2994,7 +2994,7 @@ def test_span_links_set_on_root_span_not_child(fastapi_client, tracer, fastapi_t
             _HTTP_HEADER_B3_SPAN_ID: "7197677932a62370",
         },
     ),
-    # B3 Single Header
+    # B3
     (
         "valid_b3_single_style",
         [PROPAGATION_STYLE_B3_SINGLE],