ext/opentracing-shim: implement inject and extract (open-telemetry#256)

This commit implements inject() and extract() support for TEXT_MAP and
HTTP_HEADERS formats by using the configured OpenTelemetry propagators.

The support for binary propagators is not completed on opentelemetry-python so
this commit does not include for such format.

CONTRIBUTING.md

@@ -19,7 +19,7 @@ If you are looking for someone to help you find a starting point and be a resour
 Gitter and find a buddy!
 
 1. Join [Gitter.im](https://gitter.im) and join our [chat room](https://gitter.im/open-telemetry/opentelemetry-python).
-2. Post in the room with an introduction to yourself, what area you are interested in (checks issues marked "Help Wanted"),
+2. Post in the room with an introduction to yourself, what area you are interested in (check issues marked "Help Wanted"),
 and say you are looking for a buddy. We will match you with someone who has experience in that area.
 
 Your OpenTelemetry buddy is your resource to talk to directly on all aspects of contributing to OpenTelemetry: providing
@@ -37,7 +37,7 @@ You can run:
   under multiple Python versions
 - `tox -e docs` to regenerate the API docs
 - `tox -e test-api` and `tox -e test-sdk` to run the API and SDK unit tests
-- `tox -e py37-test-api` to e.g. run the the API unit tests under a specific
+- `tox -e py37-test-api` to e.g. run the API unit tests under a specific
   Python version
 - `tox -e lint` to run lint checks on all code
 
@@ -115,7 +115,7 @@ It's especially valuable to read through the [library guidelines](https://github
 OpenTelemetry is an evolving specification, one where the desires and
 use cases are clear, but the method to satisfy those uses cases are not.
 
-As such, Contributions should provide functionality and behavior that 
+As such, contributions should provide functionality and behavior that 
 conforms to the specification, but the interface and structure is flexible.
 
 It is preferable to have contributions follow the idioms of the language 

ext/opentelemetry-ext-opentracing-shim/CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ## Unreleased
 
+- Implement extract and inject support for HTTP_HEADERS and TEXT_MAP formats.
+
 ## 0.2a0
 
 Released 2019-10-29

ext/opentelemetry-ext-opentracing-shim/src/opentelemetry/ext/opentracing_shim/__init__.py

@@ -17,6 +17,7 @@
 import opentracing
 from deprecated import deprecated
 
+from opentelemetry import propagators
 from opentelemetry.ext.opentracing_shim import util
 
 logger = logging.getLogger(__name__)
@@ -184,6 +185,10 @@ class TracerShim(opentracing.Tracer):
     def __init__(self, tracer):
         super().__init__(scope_manager=ScopeManagerShim(self))
         self._otel_tracer = tracer
+        self._supported_formats = (
+            opentracing.Format.TEXT_MAP,
+            opentracing.Format.HTTP_HEADERS,
+        )
 
     def unwrap(self):
         """Returns the wrapped OpenTelemetry `Tracer` object."""
@@ -249,16 +254,32 @@ def start_span(
 
     def inject(self, span_context, format, carrier):
         # pylint: disable=redefined-builtin
-        logger.warning(
-            "Calling unimplemented method inject() on class %s",
-            self.__class__.__name__,
+        # This implementation does not perform the injecting by itself but
+        # uses the configured propagators in opentelemetry.propagators.
+        # TODO: Support Format.BINARY once it is supported in
+        # opentelemetry-python.
+        if format not in self._supported_formats:
+            raise opentracing.UnsupportedFormatException
+
+        propagator = propagators.get_global_httptextformat()
+        propagator.inject(
+            span_context.unwrap(), type(carrier).__setitem__, carrier
         )
-        # TODO: Implement.
 
     def extract(self, format, carrier):
         # pylint: disable=redefined-builtin
-        logger.warning(
-            "Calling unimplemented method extract() on class %s",
-            self.__class__.__name__,
-        )
-        # TODO: Implement.
+        # This implementation does not perform the extracing by itself but
+        # uses the configured propagators in opentelemetry.propagators.
+        # TODO: Support Format.BINARY once it is supported in
+        # opentelemetry-python.
+        if format not in self._supported_formats:
+            raise opentracing.UnsupportedFormatException
+
+        def get_as_list(dict_object, key):
+            value = dict_object.get(key)
+            return [value] if value is not None else []
+
+        propagator = propagators.get_global_httptextformat()
+        otel_context = propagator.extract(get_as_list, carrier)
+
+        return SpanContextShim(otel_context)

ext/opentelemetry-ext-opentracing-shim/tests/test_shim.py

@@ -18,7 +18,8 @@
 import opentracing
 
 import opentelemetry.ext.opentracing_shim as opentracingshim
-from opentelemetry import trace
+from opentelemetry import propagators, trace
+from opentelemetry.context.propagation.httptextformat import HTTPTextFormat
 from opentelemetry.ext.opentracing_shim import util
 from opentelemetry.sdk.trace import Tracer
 
@@ -40,6 +41,17 @@ def setUpClass(cls):
 
         trace.set_preferred_tracer_implementation(lambda T: Tracer())
 
+        # Save current propagator to be restored on teardown.
+        cls._previous_propagator = propagators.get_global_httptextformat()
+
+        # Set mock propagator for testing.
+        propagators.set_global_httptextformat(MockHTTPTextFormat)
+
+    @classmethod
+    def tearDownClass(cls):
+        # Restore previous propagator.
+        propagators.set_global_httptextformat(cls._previous_propagator)
+
     def test_shim_type(self):
         # Verify shim is an OpenTracing tracer.
         self.assertIsInstance(self.shim, opentracing.Tracer)
@@ -453,3 +465,91 @@ def test_span_on_error(self):
         self.assertEqual(
             scope.span.unwrap().events[0].attributes["error.kind"], Exception
         )
+
+    def test_inject_http_headers(self):
+        """Test `inject()` method for Format.HTTP_HEADERS."""
+
+        otel_context = trace.SpanContext(trace_id=1220, span_id=7478)
+        context = opentracingshim.SpanContextShim(otel_context)
+
+        headers = {}
+        self.shim.inject(context, opentracing.Format.HTTP_HEADERS, headers)
+        self.assertEqual(headers[MockHTTPTextFormat.TRACE_ID_KEY], str(1220))
+        self.assertEqual(headers[MockHTTPTextFormat.SPAN_ID_KEY], str(7478))
+
+    def test_inject_text_map(self):
+        """Test `inject()` method for Format.TEXT_MAP."""
+
+        otel_context = trace.SpanContext(trace_id=1220, span_id=7478)
+        context = opentracingshim.SpanContextShim(otel_context)
+
+        # Verify Format.TEXT_MAP
+        text_map = {}
+        self.shim.inject(context, opentracing.Format.TEXT_MAP, text_map)
+        self.assertEqual(text_map[MockHTTPTextFormat.TRACE_ID_KEY], str(1220))
+        self.assertEqual(text_map[MockHTTPTextFormat.SPAN_ID_KEY], str(7478))
+
+    def test_inject_binary(self):
+        """Test `inject()` method for Format.BINARY."""
+
+        otel_context = trace.SpanContext(trace_id=1220, span_id=7478)
+        context = opentracingshim.SpanContextShim(otel_context)
+
+        # Verify exception for non supported binary format.
+        with self.assertRaises(opentracing.UnsupportedFormatException):
+            self.shim.inject(context, opentracing.Format.BINARY, bytearray())
+
+    def test_extract_http_headers(self):
+        """Test `extract()` method for Format.HTTP_HEADERS."""
+
+        carrier = {
+            MockHTTPTextFormat.TRACE_ID_KEY: 1220,
+            MockHTTPTextFormat.SPAN_ID_KEY: 7478,
+        }
+
+        ctx = self.shim.extract(opentracing.Format.HTTP_HEADERS, carrier)
+        self.assertEqual(ctx.unwrap().trace_id, 1220)
+        self.assertEqual(ctx.unwrap().span_id, 7478)
+
+    def test_extract_text_map(self):
+        """Test `extract()` method for Format.TEXT_MAP."""
+
+        carrier = {
+            MockHTTPTextFormat.TRACE_ID_KEY: 1220,
+            MockHTTPTextFormat.SPAN_ID_KEY: 7478,
+        }
+
+        ctx = self.shim.extract(opentracing.Format.TEXT_MAP, carrier)
+        self.assertEqual(ctx.unwrap().trace_id, 1220)
+        self.assertEqual(ctx.unwrap().span_id, 7478)
+
+    def test_extract_binary(self):
+        """Test `extract()` method for Format.BINARY."""
+
+        # Verify exception for non supported binary format.
+        with self.assertRaises(opentracing.UnsupportedFormatException):
+            self.shim.extract(opentracing.Format.BINARY, bytearray())
+
+
+class MockHTTPTextFormat(HTTPTextFormat):
+    """Mock propagator for testing purposes."""
+
+    TRACE_ID_KEY = "mock-traceid"
+    SPAN_ID_KEY = "mock-spanid"
+
+    @classmethod
+    def extract(cls, get_from_carrier, carrier):
+        trace_id_list = get_from_carrier(carrier, cls.TRACE_ID_KEY)
+        span_id_list = get_from_carrier(carrier, cls.SPAN_ID_KEY)
+
+        if not trace_id_list or not span_id_list:
+            return trace.INVALID_SPAN_CONTEXT
+
+        return trace.SpanContext(
+            trace_id=int(trace_id_list[0]), span_id=int(span_id_list[0])
+        )
+
+    @classmethod
+    def inject(cls, context, set_in_carrier, carrier):
+        set_in_carrier(carrier, cls.TRACE_ID_KEY, str(context.trace_id))
+        set_in_carrier(carrier, cls.SPAN_ID_KEY, str(context.span_id))

ext/opentelemetry-ext-wsgi/README.rst

@@ -3,8 +3,8 @@ OpenTelemetry WSGI Middleware
 
 |pypi|
 
-.. |pypi| image:: https://badge.fury.io/py/opentelemetry-wsgi.svg
-   :target: https://pypi.org/project/opentelemetry-opentracing-wsgi/
+.. |pypi| image:: https://badge.fury.io/py/opentelemetry-ext-wsgi.svg
+   :target: https://pypi.org/project/opentelemetry-ext-wsgi/
 
 
 This library provides a WSGI middleware that can be used on any WSGI framework
@@ -15,7 +15,7 @@ Installation
 
 ::
 
-    pip install opentelemetry-opentracing-wsgi
+    pip install opentelemetry-ext-wsgi
 
 
 Usage (Flask)

opentelemetry-api/src/opentelemetry/context/propagation/tracecontexthttptextformat.py

@@ -21,7 +21,7 @@
 _T = typing.TypeVar("_T")
 
 #    Keys and values are strings of up to 256 printable US-ASCII characters.
-#    Implementations should conform to the the `W3C Trace Context - Tracestate`_
+#    Implementations should conform to the `W3C Trace Context - Tracestate`_
 #    spec, which describes additional restrictions on valid field values.
 #
 #    .. _W3C Trace Context - Tracestate:

opentelemetry-api/src/opentelemetry/trace/__init__.py

@@ -285,7 +285,7 @@ class TraceState(typing.Dict[str, str]):
     """A list of key-value pairs representing vendor-specific trace info.
 
     Keys and values are strings of up to 256 printable US-ASCII characters.
-    Implementations should conform to the the `W3C Trace Context - Tracestate`_
+    Implementations should conform to the `W3C Trace Context - Tracestate`_
     spec, which describes additional restrictions on valid field values.
 
     .. _W3C Trace Context - Tracestate: