[PPP-502] TKMS - Add decorator for message headers

CHANGELOG.md

@@ -5,6 +5,10 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [0.30.0] 2024-08-06
+### Added
+- Added `ITkmsMessageDecorator` that kicks in before message is registered and adds custom headers
+
 ## [0.29.1] 2024-07-25
 ### Fixed
 - Fixed the prometheus metrics cant cast metric type gauge to info issue.

tw-tkms-starter/src/main/java/com/transferwise/kafka/tkms/TransactionalKafkaMessageSender.java

@@ -8,6 +8,7 @@
 import com.transferwise.kafka.tkms.TransactionContext.ShardPartitionMessages;
 import com.transferwise.kafka.tkms.api.ITkmsEventsListener;
 import com.transferwise.kafka.tkms.api.ITkmsEventsListener.MessageRegisteredEvent;
+import com.transferwise.kafka.tkms.api.ITkmsMessageDecorator;
 import com.transferwise.kafka.tkms.api.ITransactionalKafkaMessageSender;
 import com.transferwise.kafka.tkms.api.TkmsMessage;
 import com.transferwise.kafka.tkms.api.TkmsMessage.Header;
@@ -62,6 +63,8 @@ protected void setTkmsDaoProvider(ITkmsDaoProvider tkmsDaoProvider) {
   private IProblemNotifier problemNotifier;
   @Autowired
   private ITkmsTopicValidator tkmsTopicValidator;
+  @Autowired
+  private List<ITkmsMessageDecorator> messageDecorators;
 
   private volatile List<ITkmsEventsListener> tkmsEventsListeners;
   private RateLimiter errorLogRateLimiter = RateLimiter.create(2);
@@ -144,10 +147,10 @@ protected void checkActiveTransaction(int shard, boolean transactionActive, bool
 
   @Override
   public SendMessagesResult sendMessages(SendMessagesRequest request) {
-    var transactionActive = TransactionSynchronizationManager.isActualTransactionActive();
-
+    request.getTkmsMessages().forEach(message -> messageDecorators.forEach(message::accept));
     validateMessages(request);
 
+    var transactionActive = TransactionSynchronizationManager.isActualTransactionActive();
     var validatedTopics = new HashSet<String>();
 
     int seq = 0;
@@ -250,7 +253,7 @@ public SendMessageResult sendMessage(SendMessageRequest request) {
 
     var message = request.getTkmsMessage();
     var shardPartition = getShardPartition(message);
-
+    messageDecorators.forEach(message::accept);
     try {
       shardPartition.putIntoMdc();
 

tw-tkms-starter/src/main/java/com/transferwise/kafka/tkms/api/ITkmsMessageDecorator.java

@@ -0,0 +1,11 @@
+package com.transferwise.kafka.tkms.api;
+
+import com.transferwise.kafka.tkms.api.TkmsMessage.Header;
+import java.util.List;
+
+public interface ITkmsMessageDecorator {
+
+  default List<Header> getHeaders(TkmsMessage message) {
+    return List.of();
+  }
+}

tw-tkms-starter/src/main/java/com/transferwise/kafka/tkms/api/TkmsMessage.java

@@ -79,6 +79,14 @@ public TkmsMessage addHeader(Header header) {
     return this;
   }
 
+  public TkmsMessage accept(ITkmsMessageDecorator decorator) {
+    var headers = decorator.getHeaders(this);
+    if (headers != null) {
+      headers.forEach(this::addHeader);
+    }
+    return this;
+  }
+
   /**
    * Forces specified compression.
    */

tw-tkms-starter/src/main/java/com/transferwise/kafka/tkms/config/TkmsAutoConfiguration.java

@@ -6,7 +6,10 @@
 import com.transferwise.common.baseutils.meters.cache.MeterCache;
 import com.transferwise.common.baseutils.transactionsmanagement.ITransactionsHelper;
 import com.transferwise.common.baseutils.transactionsmanagement.TransactionsHelper;
+import com.transferwise.kafka.tkms.api.ITkmsMessageDecorator;
 import io.micrometer.core.instrument.MeterRegistry;
+import java.util.Collections;
+import java.util.List;
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.boot.autoconfigure.AutoConfigureAfter;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
@@ -39,5 +42,11 @@ public IMeterCache twDefaultMeterCache(MeterRegistry meterRegistry) {
   public TransactionsHelper twTransactionsHelper() {
     return new TransactionsHelper();
   }
+
+  @Bean
+  @ConditionalOnMissingBean(ITkmsMessageDecorator.class)
+  public List<ITkmsMessageDecorator> messageDecorators() {
+    return Collections.emptyList();
+  }
 
 }

tw-tkms-starter/src/test/java/com/transferwise/kafka/tkms/MessageDecorationTest.java

@@ -0,0 +1,64 @@
+package com.transferwise.kafka.tkms;
+
+import static org.awaitility.Awaitility.await;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import com.transferwise.common.baseutils.transactionsmanagement.ITransactionsHelper;
+import com.transferwise.kafka.tkms.api.ITransactionalKafkaMessageSender.SendMessagesRequest;
+import com.transferwise.kafka.tkms.api.TkmsMessage;
+import com.transferwise.kafka.tkms.test.BaseIntTest;
+import com.transferwise.kafka.tkms.test.ITkmsSentMessagesCollector.SentMessage;
+import com.transferwise.kafka.tkms.test.TestMessagesInterceptor;
+import com.transferwise.kafka.tkms.test.TestProperties;
+import java.nio.charset.StandardCharsets;
+import java.util.stream.StreamSupport;
+import lombok.extern.slf4j.Slf4j;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+
+@Slf4j
+class MessageDecorationTest extends BaseIntTest {
+
+  @Autowired
+  private TestMessagesInterceptor testMessagesInterceptor;
+  @Autowired
+  private TransactionalKafkaMessageSender transactionalKafkaMessageSender;
+  @Autowired
+  private TestProperties testProperties;
+  @Autowired
+  private ITransactionsHelper transactionsHelper;
+
+  @AfterEach
+  void cleanupTest() {
+    testMessagesInterceptor.setBeforeSendingToKafkaFunction(null);
+  }
+
+  @Test
+  void messagesAreDecorateWithJambi() {
+    byte[] someValue = "Here from the king's mountain view, Feast like a sultan I do!".getBytes(StandardCharsets.UTF_8);
+
+    String topic = testProperties.getTestTopic();
+
+    transactionsHelper.withTransaction().run(() ->
+        transactionalKafkaMessageSender.sendMessages(new SendMessagesRequest()
+            .addTkmsMessage(new TkmsMessage().setTopic(topic).setKey("adam-jones").setValue(someValue))
+            .addTkmsMessage(new TkmsMessage().setTopic(topic).setKey("danny-carey").setValue(someValue))
+        ));
+
+    await().until(() -> tkmsSentMessagesCollector.getSentMessages(topic).size() == 2);
+    var messages = tkmsSentMessagesCollector.getSentMessages(topic);
+
+    assertEquals(2, messages.size());
+    checkForHeader(messages.get(0), "tool", "jambi");
+    checkForHeader(messages.get(1), "tool", "jambi");
+  }
+
+  private void checkForHeader(SentMessage sentMessage, String key, String value) {
+    assertTrue(
+        StreamSupport.stream(sentMessage.getProducerRecord().headers().spliterator(), false)
+            .anyMatch(h -> h.key().equals(key) && value.equals(new String(h.value())))
+    );
+  }
+}

tw-tkms-starter/src/test/java/com/transferwise/kafka/tkms/test/TestMessageDecorator.java

@@ -0,0 +1,21 @@
+package com.transferwise.kafka.tkms.test;
+
+import com.transferwise.kafka.tkms.api.ITkmsMessageDecorator;
+import com.transferwise.kafka.tkms.api.TkmsMessage;
+import com.transferwise.kafka.tkms.api.TkmsMessage.Header;
+import java.util.List;
+import org.springframework.stereotype.Component;
+
+@Component
+public class TestMessageDecorator implements ITkmsMessageDecorator {
+
+  @Override
+  public List<Header> getHeaders(TkmsMessage message) {
+    var h1 = new Header().setKey("tool").setValue("jambi".getBytes());
+    if (message.getKey() == null) {
+      return List.of();
+    }
+    return List.of(h1);
+  }
+
+}