From db1eb3b985d535b7a67cbec0276196a5402287af Mon Sep 17 00:00:00 2001
From: William Poteat <wpoteat@redhat.com>
Date: Mon, 19 Aug 2024 15:48:39 -0400
Subject: [PATCH] Add traceresponse header to HTTP responses

https://github.com/quarkusio/quarkus/issues/11931
---
 .../resteasy/TraceResponseFilter.java         | 22 +++++++++++++++++++
 1 file changed, 22 insertions(+)
 create mode 100644 extensions/opentelemetry/runtime/src/main/java/io/quarkus/opentelemetry/runtime/tracing/intrumentation/resteasy/TraceResponseFilter.java

diff --git a/extensions/opentelemetry/runtime/src/main/java/io/quarkus/opentelemetry/runtime/tracing/intrumentation/resteasy/TraceResponseFilter.java b/extensions/opentelemetry/runtime/src/main/java/io/quarkus/opentelemetry/runtime/tracing/intrumentation/resteasy/TraceResponseFilter.java
new file mode 100644
index 0000000000000..dd3a229b065b3
--- /dev/null
+++ b/extensions/opentelemetry/runtime/src/main/java/io/quarkus/opentelemetry/runtime/tracing/intrumentation/resteasy/TraceResponseFilter.java
@@ -0,0 +1,22 @@
+package io.quarkus.opentelemetry.runtime.tracing.intrumentation.resteasy;
+
+import org.jboss.resteasy.reactive.server.ServerResponseFilter;
+
+import io.opentelemetry.api.trace.Span;
+import io.opentelemetry.api.trace.SpanContext;
+import jakarta.ws.rs.container.ContainerResponseContext;
+
+public class TraceResponseFilter {
+
+    @ServerResponseFilter
+    public void responseBasicHeaderFilter(ContainerResponseContext responseContext) {
+        SpanContext spanContext = Span.current().getSpanContext();
+        responseContext
+            .getHeaders()
+            .putSingle(
+                "traceresponse",
+                String.format(
+                    "00-%s-%s-%s  ",
+                    spanContext.getTraceId(), spanContext.getSpanId(), spanContext.getTraceFlags()));
+    }
+}