AuditService initialization improvement : making admin client init reqired only for audit-enabled clusters

kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/audit/AuditService.java

@@ -56,14 +56,8 @@ public class AuditService implements Closeable {
   public AuditService(AdminClientService adminClientService, ClustersStorage clustersStorage) {
     Map<String, AuditWriter> auditWriters = new HashMap<>();
     for (var cluster : clustersStorage.getKafkaClusters()) {
-      ReactiveAdminClient adminClient;
-      try {
-        adminClient = adminClientService.get(cluster).block();
-      } catch (Exception e) {
-        printAuditInitError(cluster, "Error connect to cluster", e);
-        continue;
-      }
-      createAuditWriter(cluster, adminClient, () -> createProducer(cluster, AUDIT_PRODUCER_CONFIG))
+      Supplier<ReactiveAdminClient> adminClientSupplier = () -> adminClientService.get(cluster).block();
+      createAuditWriter(cluster, adminClientSupplier, () -> createProducer(cluster, AUDIT_PRODUCER_CONFIG))
           .ifPresent(writer -> auditWriters.put(cluster.getName(), writer));
     }
     this.auditWriters = auditWriters;
@@ -76,7 +70,7 @@ public class AuditService implements Closeable {
 
   @VisibleForTesting
   static Optional<AuditWriter> createAuditWriter(KafkaCluster cluster,
-                                                 ReactiveAdminClient ac,
+                                                 Supplier<ReactiveAdminClient> acSupplier,
                                                  Supplier<KafkaProducer<byte[], byte[]>> producerFactory) {
     var auditProps = cluster.getOriginalProperties().getAudit();
     if (auditProps == null) {
@@ -87,29 +81,39 @@ public class AuditService implements Closeable {
     if (!topicAudit && !consoleAudit) {
       return Optional.empty();
     }
+    if (!topicAudit) {
+      // console logging only
+      log.info("Audit service initialized for cluster (console only) '{}'", cluster.getName());
+      return Optional.of(new AuditWriter(cluster.getName(), null, null, AUDIT_LOGGER));
+    }
     String auditTopicName = Optional.ofNullable(auditProps.getTopic()).orElse(DEFAULT_AUDIT_TOPIC_NAME);
-    @Nullable KafkaProducer<byte[], byte[]> producer = null;
-    if (topicAudit && createTopicIfNeeded(cluster, ac, auditTopicName, auditProps)) {
-      producer = producerFactory.get();
+    if (createTopicIfNeeded(cluster, acSupplier, auditTopicName, auditProps)) {
+      log.info("Audit service initialized for cluster '{}'", cluster.getName());
+      return Optional.of(
+          new AuditWriter(cluster.getName(),
+              auditTopicName,
+              producerFactory.get(),
+              consoleAudit ? AUDIT_LOGGER : null
+          )
+      );
     }
-    log.info("Audit service initialized for cluster '{}'", cluster.getName());
-    return Optional.of(
-        new AuditWriter(
-            cluster.getName(),
-            auditTopicName,
-            producer,
-            consoleAudit ? AUDIT_LOGGER : null
-        )
-    );
+    return Optional.empty();
   }
 
   /**
    * return true if topic created/existing and producing can be enabled.
    */
   private static boolean createTopicIfNeeded(KafkaCluster cluster,
-                                             ReactiveAdminClient ac,
+                                             Supplier<ReactiveAdminClient> acSupplier,
                                              String auditTopicName,
                                              ClustersProperties.AuditProperties auditProps) {
+    ReactiveAdminClient ac;
+    try {
+      ac = acSupplier.get();
+    } catch (Exception e) {
+      printAuditInitError(cluster, "Error connect to cluster", e);
+      return false;
+    }
     boolean topicExists;
     try {
       topicExists = ac.listTopics(true).block().contains(auditTopicName);

kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/audit/AuditWriter.java

@@ -18,7 +18,7 @@ import org.slf4j.Logger;
 
 @Slf4j
 record AuditWriter(String clusterName,
-                   String targetTopic,
+                   @Nullable String targetTopic,
                    @Nullable KafkaProducer<byte[], byte[]> producer,
                    @Nullable Logger consoleLogger) implements Closeable {
 
@@ -43,7 +43,7 @@ record AuditWriter(String clusterName,
     if (consoleLogger != null) {
       consoleLogger.info(json);
     }
-    if (producer != null) {
+    if (targetTopic != null && producer != null) {
       producer.send(
           new ProducerRecord<>(targetTopic, null, json.getBytes(UTF_8)),
           (metadata, ex) -> {