Generate instrumentation packages setup.py files (open-telemetry#474)

All instrumentations packages have almost exactly same setup.py files.
This commit adds a python script that generates it from a source
template. This dramatically reduces the time and effort required to
update all instrumentation setup.py files, and also reduces chances of
making manual mistakes.

Author: owais

Diff for: CHANGELOG.md

@@ -18,6 +18,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   ([#480](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/480))
 - Fix entrypoint for ottrace propagator
   ([#492](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/492))
+- `opentelemetry-propagator-ot-trace` Fix case sensitivity when handling baggage
+  ([#484](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/484))
 
 ### Added
 - Move `opentelemetry-instrumentation` from core repository

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

@@ -95,7 +95,7 @@ def extract(
 
             for key in getter.keys(carrier):
 
-                if not key.startswith(OT_BAGGAGE_PREFIX):
+                if not key.lower().startswith(OT_BAGGAGE_PREFIX.lower()):
                     continue
 
                 baggage[

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

@@ -359,6 +359,37 @@ def test_extract_baggage(self):
         self.assertEqual(baggage["abc"], "abc")
         self.assertEqual(baggage["def"], "def")
 
+        context = self.ot_trace_propagator.extract(
+            {
+                OT_TRACE_ID_HEADER: "64fe8b2a57d3eff7",
+                OT_SPAN_ID_HEADER: "e457b5a2e4d86bd1",
+                OT_SAMPLED_HEADER: "false",
+                "".join(
+                    [
+                        "".join(
+                            [
+                                OT_BAGGAGE_PREFIX[:3].lower(),
+                                OT_BAGGAGE_PREFIX[3:].upper()
+                            ]
+                        ),
+                        "abc"
+                    ]
+                ): "abc",
+                "".join([OT_BAGGAGE_PREFIX, "def"]): "def",
+            },
+        )
+        span_context = get_current_span(context).get_span_context()
+
+        self.assertEqual(hex(span_context.trace_id)[2:], "64fe8b2a57d3eff7")
+        self.assertEqual(hex(span_context.span_id)[2:], "e457b5a2e4d86bd1")
+        self.assertTrue(span_context.is_remote)
+        self.assertEqual(span_context.trace_flags, TraceFlags.DEFAULT)
+
+        baggage = get_all(context)
+
+        self.assertEqual(baggage["abc"], "abc")
+        self.assertEqual(baggage["def"], "def")
+
     def test_extract_empty(self):
         "Test extraction when no headers are present"