Default w3c sampled flag to 01 so the OTEL collector does not ignore the spans (#105)

Receiving OTEL instrumentation ignores spans coming with the 00 sampled flag.

This is a stop-gap measure to ensure w3c parser hooks work with an OTEL receiver. Ideally, we would like to set the sampled flag based on an actual sampler, but that requires further investigation.

Author: vreynolds

beeline-core/src/main/java/io/honeycomb/beeline/tracing/propagation/W3CPropagationCodec.java

@@ -173,7 +173,7 @@ public Optional<Map<String, String>> encode(PropagationContext context) {
             return Optional.empty();
         }
 
-        final String traceParent = String.join(SEGMENT_SEPARATOR, DEFAULT_VERSION, context.getTraceId(), context.getSpanId(), NOT_SAMPLED_TRACEFLAGS);
+        final String traceParent = String.join(SEGMENT_SEPARATOR, DEFAULT_VERSION, context.getTraceId(), context.getSpanId(), SAMPLED_TRACEFLAGS);
 
         // If no dataset or tracefields, just return trace parent header
         if (context.getDataset() == null && context.getTraceFields().isEmpty()) {

beeline-core/src/test/java/io/honeycomb/beeline/tracing/propagation/W3CPropagationCodecTest.java

@@ -243,7 +243,7 @@ public void GIVEN_aPopulatedContext_EXPECT_aValidHeaderValue() {
         final Map<String, String> encoded = codec.encode(new PropagationContext(traceId, spanId, null, null)).get();
 
         assertThat(encoded).isEqualTo(
-            Collections.singletonMap(W3CPropagationCodec.W3C_TRACEPARENT_HEADER, String.join("-", "00", traceId, spanId, "00"))
+            Collections.singletonMap(W3CPropagationCodec.W3C_TRACEPARENT_HEADER, String.join("-", "00", traceId, spanId, "01"))
         );
     }
 
@@ -254,11 +254,11 @@ public void GIVEN_aPopulatedContextWithDataset_EXPECT_aValidHeaderValueWithTrace
         String dataset = "test-dataset";
 
         final Map<String, String> headers = new HashMap<>();
-        headers.put(W3CPropagationCodec.W3C_TRACEPARENT_HEADER, String.join("-", "00", traceId, spanId, "00"));
+        headers.put(W3CPropagationCodec.W3C_TRACEPARENT_HEADER, String.join("-", "00", traceId, spanId, "01"));
         headers.put(W3CPropagationCodec.W3C_TRACESTATE_HEADER, "hny=ZGF0YXNldD10ZXN0LWRhdGFzZXQ=");
 
         final Map<String, String> encoded = codec.encode(new PropagationContext(traceId, spanId, dataset, null)).get();
-        assertThat(headers).isEqualTo(encoded);
+        assertThat(encoded).isEqualTo(headers);
     }
 
     @Test
@@ -270,11 +270,11 @@ public void GIVEN_aPopulatedContextWithFields_EXPECT_aValidHeaderValueWithTraceS
         fields.put("one", "two");
 
         final Map<String, String> headers = new HashMap<>();
-        headers.put(W3CPropagationCodec.W3C_TRACEPARENT_HEADER, String.join("-", "00", traceId, spanId, "00"));
+        headers.put(W3CPropagationCodec.W3C_TRACEPARENT_HEADER, String.join("-", "00", traceId, spanId, "01"));
         headers.put(W3CPropagationCodec.W3C_TRACESTATE_HEADER, "hny=Zm9vPWJhcixvbmU9dHdv");
 
         final Map<String, String> encoded = codec.encode(new PropagationContext(traceId, spanId, null, fields)).get();
-        assertThat(headers).isEqualTo(encoded);
+        assertThat(encoded).isEqualTo(headers);
     }
 
     @Test
@@ -287,10 +287,10 @@ public void GIVEN_aPopulatedContextWithDatasetAndFields_EXPECT_aValidHeaderValue
         fields.put("one", "two");
 
         final Map<String, String> headers = new HashMap<>();
-        headers.put(W3CPropagationCodec.W3C_TRACEPARENT_HEADER, String.join("-", "00", traceId, spanId, "00"));
+        headers.put(W3CPropagationCodec.W3C_TRACEPARENT_HEADER, String.join("-", "00", traceId, spanId, "01"));
         headers.put(W3CPropagationCodec.W3C_TRACESTATE_HEADER,  "hny=ZGF0YXNldD10ZXN0LWRhdGFzZXQsZm9vPWJhcixvbmU9dHdv");
 
         final Map<String, String> encoded = codec.encode(new PropagationContext(traceId, spanId, dataset, fields)).get();
-        assertThat(headers).isEqualTo(encoded);
+        assertThat(encoded).isEqualTo(headers);
     }
 }