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clients/clients-integration-tests/src/test/java/org/apache/kafka/clients/ClientConfigPushIntegrationTest.java

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+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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.apache.kafka.clients;
+
+import org.apache.kafka.clients.consumer.Consumer;
+import org.apache.kafka.clients.consumer.ConsumerConfig;
+import org.apache.kafka.clients.consumer.KafkaConsumer;
+import org.apache.kafka.clients.producer.KafkaProducer;
+import org.apache.kafka.clients.producer.Producer;
+import org.apache.kafka.clients.producer.ProducerConfig;
+import org.apache.kafka.common.Uuid;
+import org.apache.kafka.common.errors.ClientConfigPolicyException;
+import org.apache.kafka.common.errors.UnknownConfigProfileException;
+import org.apache.kafka.common.serialization.StringDeserializer;
+import org.apache.kafka.common.serialization.StringSerializer;
+import org.apache.kafka.common.test.ClusterInstance;
+import org.apache.kafka.common.test.api.ClusterConfigProperty;
+import org.apache.kafka.common.test.api.ClusterTest;
+import org.apache.kafka.common.test.api.ClusterTestDefaults;
+import org.apache.kafka.server.config.ServerLogConfigs;
+import org.apache.kafka.server.policy.ClientConfigPolicy;
+import org.apache.kafka.server.policy.ClientConfigProfileKeys;
+import org.apache.kafka.server.policy.ClientProfile;
+import org.apache.kafka.server.policy.ClientPushConfigData;
+import org.junit.jupiter.api.BeforeEach;
+
+import java.util.Collections;
+import java.util.Map;
+import java.util.Optional;
+import java.util.Set;
+import java.util.SortedSet;
+import java.util.TreeSet;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.atomic.AtomicInteger;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+/**
+ * Integration tests for the client configuration push handshake (KIP-CFG).
+ * <p>
+ * Tests the end-to-end flow:
+ * 1. Client sends GetConfigProfileKeys request
+ * 2. Broker responds with profile keys and CRC
+ * 3. Client sends PushConfig request with collected configs
+ * 4. Broker validates and processes the config
+ */
+@ClusterTestDefaults(
+    brokers = 1,
+    serverProperties = {
+        @ClusterConfigProperty(key = ServerLogConfigs.CLIENT_CONFIG_POLICY_CLASS_NAME_CONFIG,
+            value = "org.apache.kafka.clients.ClientConfigPushIntegrationTest$TestClientConfigPolicy"),
+        @ClusterConfigProperty(key = ServerLogConfigs.CLIENT_CONFIG_MAX_BYTES_CONFIG, value = "1048576")
+    }
+)
+public class ClientConfigPushIntegrationTest {
+
+    private final ClusterInstance clusterInstance;
+    private TestClientConfigPolicy clientConfigPolicy;
+
+    public ClientConfigPushIntegrationTest(ClusterInstance clusterInstance) {
+        this.clusterInstance = clusterInstance;
+    }
+
+    @BeforeEach
+    public void setup() throws InterruptedException {
+        clusterInstance.waitForReadyBrokers();
+        clientConfigPolicy = new TestClientConfigPolicy();
+    }
+
+    @ClusterTest
+    public void testProducerConfigPushHandshake() throws Exception {
+        Map<String, Object> producerConfig = new java.util.HashMap<>();
+        producerConfig.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, clusterInstance.bootstrapServers());
+        producerConfig.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, StringSerializer.class.getName());
+        producerConfig.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, StringSerializer.class.getName());
+        producerConfig.put(ProducerConfig.CLIENT_ID_CONFIG, "test-producer-config-push");
+        producerConfig.put(CommonClientConfigs.ENABLE_CONFIGS_PUSH_CONFIG, true);
+
+        try (Producer<String, String> producer = new KafkaProducer<>(producerConfig)) {
+            // Give time for handshake to complete
+            Thread.sleep(2000);
+
+            // Verify policy was called
+            assertTrue(clientConfigPolicy.profileKeysCallCount.get() > 0, "profileKeys() should have been called");
+            assertTrue(clientConfigPolicy.processCallCount.get() > 0, "process() should have been called");
+
+            // Verify we received a client profile
+            assertFalse(clientConfigPolicy.receivedProfiles.isEmpty(), "Should have received client profile");
+
+            // Verify we received configs
+            assertFalse(clientConfigPolicy.receivedConfigs.isEmpty(), "Should have received client configs");
+
+            // Verify configs were collected (should have client.id but not bootstrap.servers)
+            Map<String, String> configs = clientConfigPolicy.receivedConfigs.values().iterator().next();
+            assertTrue(configs.containsKey(ProducerConfig.CLIENT_ID_CONFIG),
+                "Should contain client.id config");
+            assertFalse(configs.containsKey(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG),
+                "Should NOT contain bootstrap.servers (sensitive)");
+        }
+    }
+
+    @ClusterTest
+    public void testConsumerConfigPushHandshake() throws Exception {
+        Map<String, Object> consumerConfig = new java.util.HashMap<>();
+        consumerConfig.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, clusterInstance.bootstrapServers());
+        consumerConfig.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class.getName());
+        consumerConfig.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class.getName());
+        consumerConfig.put(ConsumerConfig.GROUP_ID_CONFIG, "test-consumer-config-push");
+        consumerConfig.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "earliest");
+        consumerConfig.put(CommonClientConfigs.ENABLE_CONFIGS_PUSH_CONFIG, true);
+
+        try (Consumer<String, String> consumer = new KafkaConsumer<>(consumerConfig)) {
+            // Give time for handshake to complete
+            Thread.sleep(2000);
+
+            // Verify policy was called
+            assertTrue(clientConfigPolicy.profileKeysCallCount.get() > 0, "profileKeys() should have been called");
+            assertTrue(clientConfigPolicy.processCallCount.get() > 0, "process() should have been called");
+
+            // Verify we received configs
+            assertFalse(clientConfigPolicy.receivedConfigs.isEmpty(), "Should have received client configs");
+
+            Map<String, String> configs = clientConfigPolicy.receivedConfigs.values().iterator().next();
+            assertTrue(configs.containsKey(ConsumerConfig.GROUP_ID_CONFIG),
+                "Should contain group.id config");
+            assertTrue(configs.containsKey(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG),
+                "Should contain auto.offset.reset config");
+        }
+    }
+
+    @ClusterTest
+    public void testConfigPushWithEmptyProfile() throws Exception {
+        // Configure policy to return empty profile (no config keys requested)
+        clientConfigPolicy.returnEmptyProfile = true;
+
+        Map<String, Object> producerConfig = new java.util.HashMap<>();
+        producerConfig.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, clusterInstance.bootstrapServers());
+        producerConfig.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, StringSerializer.class.getName());
+        producerConfig.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, StringSerializer.class.getName());
+        producerConfig.put(CommonClientConfigs.ENABLE_CONFIGS_PUSH_CONFIG, true);
+
+        try (Producer<String, String> producer = new KafkaProducer<>(producerConfig)) {
+            // Give time for handshake to complete
+            Thread.sleep(2000);
+
+            // profileKeys() should be called
+            assertTrue(clientConfigPolicy.profileKeysCallCount.get() > 0, "profileKeys() should have been called");
+
+            // But process() should NOT be called since no configs were requested
+            assertEquals(0, clientConfigPolicy.processCallCount.get(), "process() should NOT have been called with empty profile");
+        }
+    }
+
+    @ClusterTest
+    public void testConfigPushDisabled() throws Exception {
+        Map<String, Object> producerConfig = new java.util.HashMap<>();
+        producerConfig.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, clusterInstance.bootstrapServers());
+        producerConfig.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, StringSerializer.class.getName());
+        producerConfig.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, StringSerializer.class.getName());
+        // Disable config push
+        producerConfig.put(CommonClientConfigs.ENABLE_CONFIGS_PUSH_CONFIG, false);
+
+        try (Producer<String, String> producer = new KafkaProducer<>(producerConfig)) {
+            // Give time to ensure no handshake occurs
+            Thread.sleep(2000);
+
+            // Policy should NOT be called when disabled
+            assertEquals(0, clientConfigPolicy.profileKeysCallCount.get(), "profileKeys() should NOT be called when disabled");
+            assertEquals(0, clientConfigPolicy.processCallCount.get(), "process() should NOT be called when disabled");
+        }
+    }
+
+    @ClusterTest
+    public void testClientProfileContainsMetadata() throws Exception {
+        Map<String, Object> producerConfig = new java.util.HashMap<>();
+        producerConfig.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, clusterInstance.bootstrapServers());
+        producerConfig.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, StringSerializer.class.getName());
+        producerConfig.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, StringSerializer.class.getName());
+        producerConfig.put(ProducerConfig.CLIENT_ID_CONFIG, "metadata-test-producer");
+        producerConfig.put(CommonClientConfigs.ENABLE_CONFIGS_PUSH_CONFIG, true);
+
+        try (Producer<String, String> producer = new KafkaProducer<>(producerConfig)) {
+            Thread.sleep(2000);
+
+            assertFalse(clientConfigPolicy.receivedProfiles.isEmpty(), "Should have received client profile");
+            ClientProfile profile = clientConfigPolicy.receivedProfiles.values().iterator().next();
+
+            assertNotNull(profile.clientInstanceId(), "Client instance ID should not be null");
+            assertNotNull(profile.clientSoftwareName(), "Client software name should not be null");
+            assertNotNull(profile.clientSoftwareVersion(), "Client software version should not be null");
+            assertNotNull(profile.clientMetadata(), "Client metadata should not be null");
+
+            // Verify software name is populated (e.g., "apache-kafka-java")
+            assertFalse(profile.clientSoftwareName().isEmpty(),
+                "Client software name should not be empty");
+        }
+    }
+
+    @ClusterTest
+    public void testCrcBasedProfileChangeDetection() throws Exception {
+        Map<String, Object> producerConfig = new java.util.HashMap<>();
+        producerConfig.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, clusterInstance.bootstrapServers());
+        producerConfig.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, StringSerializer.class.getName());
+        producerConfig.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, StringSerializer.class.getName());
+        producerConfig.put(CommonClientConfigs.ENABLE_CONFIGS_PUSH_CONFIG, true);
+
+        try (Producer<String, String> producer = new KafkaProducer<>(producerConfig)) {
+            Thread.sleep(2000);
+
+            // Verify CRC was computed and is non-zero
+            assertTrue(clientConfigPolicy.profileKeysCallCount.get() > 0, "profileKeys() should have been called");
+
+            // The CRC should be deterministic based on the keys
+            // (We can't easily verify the exact value here, but we verified it's used)
+        }
+    }
+
+    /**
+     * Test implementation of ClientConfigPolicy for integration tests.
+     * <p>
+     * This policy:
+     * - Returns a standard set of config keys for all clients
+     * - Captures received profiles and configs for verification
+     * - Supports test scenarios via static flags
+     */
+    public static class TestClientConfigPolicy implements ClientConfigPolicy {
+
+        private final Map<Uuid, ClientProfile> receivedProfiles = new ConcurrentHashMap<>();
+        private final Map<Uuid, Map<String, String>> receivedConfigs = new ConcurrentHashMap<>();
+        private final AtomicInteger profileKeysCallCount = new AtomicInteger(0);
+        private final AtomicInteger processCallCount = new AtomicInteger(0);
+        private boolean returnEmptyProfile;
+        private boolean throwUnknownProfileOnKeys;
+        private boolean rejectNextPush;
+
+        private final SortedSet<String> standardConfigKeys = new TreeSet<>(Set.of(
+            "client.id",
+            "request.timeout.ms",
+            "retry.backoff.ms",
+            "metadata.max.age.ms",
+            "send.buffer.bytes",
+            "receive.buffer.bytes",
+            "reconnect.backoff.ms",
+            "reconnect.backoff.max.ms"
+        ));
+
+        @Override
+        public void configure(Map<String, ?> configs) {
+            // No configuration needed for test policy
+        }
+
+        @Override
+        public Set<String> reconfigurableConfigs() {
+            return Collections.emptySet();
+        }
+
+        @Override
+        public void validateReconfiguration(Map<String, ?> configs) {
+            // No reconfiguration validation needed
+        }
+
+        @Override
+        public void reconfigure(Map<String, ?> configs) {
+            // No reconfiguration needed
+        }
+
+        @Override
+        public Optional<ClientConfigProfileKeys> profileKeys(ClientProfile clientProfile) {
+            profileKeysCallCount.incrementAndGet();
+
+            // Store the profile for verification
+            receivedProfiles.put(clientProfile.clientInstanceId(), clientProfile);
+
+            if (throwUnknownProfileOnKeys) {
+                throw new UnknownConfigProfileException("Test: Unknown profile");
+            }
+
+            if (returnEmptyProfile) {
+                return Optional.empty();
+            }
+
+            // Return standard config keys
+            long crc = configurationProfileCrc(standardConfigKeys);
+            return Optional.of(new ClientConfigProfileKeys(standardConfigKeys, crc));
+        }
+
+        @Override
+        public void process(ClientPushConfigData pushConfigData) {
+            processCallCount.incrementAndGet();
+
+            // Store configs for verification
+            receivedConfigs.put(
+                pushConfigData.clientProfile().clientInstanceId(),
+                pushConfigData.configs()
+            );
+
+            if (rejectNextPush) {
+                throw new ClientConfigPolicyException("Test: Config validation failed");
+            }
+
+            // Validate that we received some configs
+            if (pushConfigData.configs().isEmpty()) {
+                throw new ClientConfigPolicyException("No configs received");
+            }
+        }
+
+        @Override
+        public void close() throws Exception {
+            // Cleanup if needed
+        }
+    }
+}