feat(samples): Add Kafka producer and consumer to Spring Boot 3 sample app

Add spring-kafka dependency and a simple Kafka producer/consumer setup
behind a 'kafka' Spring profile. Includes a REST endpoint to produce
messages and a KafkaListener that consumes them.

Kafka auto-configuration is excluded by default and only activated
when the 'kafka' profile is enabled.

Co-Authored-By: Claude <noreply@anthropic.com>

Author: adinauer

gradle/libs.versions.toml

@@ -183,6 +183,7 @@ springboot3-starter-security = { module = "org.springframework.boot:spring-boot-
 springboot3-starter-jdbc = { module = "org.springframework.boot:spring-boot-starter-jdbc", version.ref = "springboot3" }
 springboot3-starter-actuator = { module = "org.springframework.boot:spring-boot-starter-actuator", version.ref = "springboot3" }
 springboot3-starter-cache = { module = "org.springframework.boot:spring-boot-starter-cache", version.ref = "springboot3" }
+spring-kafka3 = { module = "org.springframework.kafka:spring-kafka", version = "3.3.5" }
 springboot4-otel = { module = "io.opentelemetry.instrumentation:opentelemetry-spring-boot-starter", version.ref = "otelInstrumentation" }
 springboot4-resttestclient = { module = "org.springframework.boot:spring-boot-resttestclient", version.ref = "springboot4" }
 springboot4-starter = { module = "org.springframework.boot:spring-boot-starter", version.ref = "springboot4" }

sentry-samples/sentry-samples-spring-boot-jakarta/build.gradle.kts

@@ -59,6 +59,9 @@ dependencies {
   implementation(libs.springboot3.starter.cache)
   implementation(libs.caffeine)
 
+  // kafka
+  implementation(libs.spring.kafka3)
+
   // OpenFeature SDK
   implementation(libs.openfeature)
 

sentry-samples/sentry-samples-spring-boot-jakarta/src/main/java/io/sentry/samples/spring/boot/jakarta/KafkaConsumer.java

@@ -0,0 +1,19 @@
+package io.sentry.samples.spring.boot.jakarta;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.context.annotation.Profile;
+import org.springframework.kafka.annotation.KafkaListener;
+import org.springframework.stereotype.Component;
+
+@Component
+@Profile("kafka")
+public class KafkaConsumer {
+
+  private static final Logger logger = LoggerFactory.getLogger(KafkaConsumer.class);
+
+  @KafkaListener(topics = "sentry-topic", groupId = "sentry-sample-group")
+  public void listen(String message) {
+    logger.info("Received message: {}", message);
+  }
+}

sentry-samples/sentry-samples-spring-boot-jakarta/src/main/java/io/sentry/samples/spring/boot/jakarta/KafkaController.java

@@ -0,0 +1,26 @@
+package io.sentry.samples.spring.boot.jakarta;
+
+import org.springframework.context.annotation.Profile;
+import org.springframework.kafka.core.KafkaTemplate;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+@Profile("kafka")
+@RequestMapping("/kafka")
+public class KafkaController {
+
+  private final KafkaTemplate<String, String> kafkaTemplate;
+
+  public KafkaController(KafkaTemplate<String, String> kafkaTemplate) {
+    this.kafkaTemplate = kafkaTemplate;
+  }
+
+  @GetMapping("/produce")
+  String produce(@RequestParam(defaultValue = "hello from sentry!") String message) {
+    kafkaTemplate.send("sentry-topic", message);
+    return "Message sent: " + message;
+  }
+}

sentry-samples/sentry-samples-spring-boot-jakarta/src/main/resources/application-kafka.properties

@@ -0,0 +1,9 @@
+# Kafka — activate with: --spring.profiles.active=kafka
+spring.autoconfigure.exclude=
+spring.kafka.bootstrap-servers=localhost:9092
+spring.kafka.consumer.group-id=sentry-sample-group
+spring.kafka.consumer.auto-offset-reset=earliest
+spring.kafka.consumer.key-deserializer=org.apache.kafka.common.serialization.StringDeserializer
+spring.kafka.consumer.value-deserializer=org.apache.kafka.common.serialization.StringDeserializer
+spring.kafka.producer.key-serializer=org.apache.kafka.common.serialization.StringSerializer
+spring.kafka.producer.value-serializer=org.apache.kafka.common.serialization.StringSerializer

sentry-samples/sentry-samples-spring-boot-jakarta/src/main/resources/application.properties

@@ -37,6 +37,10 @@ spring.quartz.job-store-type=memory
 
 # Cache tracing
 sentry.enable-cache-tracing=true
+
+# Kafka is only active with the 'kafka' profile (--spring.profiles.active=kafka)
+spring.autoconfigure.exclude=org.springframework.boot.autoconfigure.kafka.KafkaAutoConfiguration
+
 spring.cache.cache-names=todos
 spring.cache.caffeine.spec=maximumSize=500,expireAfterAccess=600s