lowercase all http header and rpc metadata keys (#250)

Author: davexroth

javaagent-core/src/main/java/org/hypertrace/agent/core/instrumentation/HypertraceSemanticAttributes.java

@@ -30,11 +30,11 @@ private HypertraceSemanticAttributes() {}
   public static final String ADDITIONAL_DATA_SPAN_NAME = "additional-data";
 
   public static AttributeKey<String> httpRequestHeader(String header) {
-    return AttributeKey.stringKey("http.request.header." + header);
+    return AttributeKey.stringKey("http.request.header." + header.toLowerCase());
   }
 
   public static AttributeKey<String> httpResponseHeader(String header) {
-    return AttributeKey.stringKey("http.response.header." + header);
+    return AttributeKey.stringKey("http.response.header." + header.toLowerCase());
   }
 
   public static final AttributeKey<String> HTTP_REQUEST_BODY =
@@ -51,10 +51,10 @@ public static AttributeKey<String> httpResponseHeader(String header) {
       AttributeKey.stringKey("rpc.response.body");
 
   public static final AttributeKey<String> rpcRequestMetadata(String key) {
-    return AttributeKey.stringKey("rpc.request.metadata." + key);
+    return AttributeKey.stringKey("rpc.request.metadata." + key.toLowerCase());
   }
 
   public static final AttributeKey<String> rpcResponseMetadata(String key) {
-    return AttributeKey.stringKey("rpc.response.metadata." + key);
+    return AttributeKey.stringKey("rpc.response.metadata." + key.toLowerCase());
   }
 }

javaagent-core/src/test/java/org/hypertrace/agent/core/instrumentation/HypertraceSemanticAttributesTest.java

@@ -0,0 +1,50 @@
+/*
+ * Copyright The Hypertrace Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.hypertrace.agent.core.instrumentation;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+public class HypertraceSemanticAttributesTest {
+
+  @Test
+  public void caseInsensitiveHttpRequestHeader() {
+    Assertions.assertEquals(
+        "http.request.header.content-type",
+        HypertraceSemanticAttributes.httpRequestHeader("Content-Type").getKey());
+  }
+
+  @Test
+  public void caseInsensitiveHttpResponseHeader() {
+    Assertions.assertEquals(
+        "http.response.header.content-type",
+        HypertraceSemanticAttributes.httpResponseHeader("Content-Type").getKey());
+  }
+
+  @Test
+  public void caseInsensitiveRpcRequestMetadata() {
+    Assertions.assertEquals(
+        "rpc.request.metadata.md", HypertraceSemanticAttributes.rpcRequestMetadata("MD").getKey());
+  }
+
+  @Test
+  public void caseInsensitiveRpcResponseMetadata() {
+    Assertions.assertEquals(
+        "rpc.response.metadata.md",
+        HypertraceSemanticAttributes.rpcResponseMetadata("MD").getKey());
+  }
+}