Fix: Add EnvironmentPostProcessor for conditional RabbitMQ/Kafka exclusion

pom.xml

@@ -91,13 +91,13 @@
             <scope>provided</scope>
         </dependency>
 
-        <!-- Apache Kafka (Optional) -->
+        <!-- Apache Kafka -->
         <dependency>
             <groupId>org.springframework.kafka</groupId>
             <artifactId>spring-kafka</artifactId>
         </dependency>
 
-        <!-- RabbitMQ (Optional) -->
+        <!-- RabbitMQ -->
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-amqp</artifactId>

src/main/java/org/fireflyframework/eda/config/FireflyEdaEnvironmentPostProcessor.java

@@ -0,0 +1,131 @@
+/*
+ * Copyright 2024-2026 Firefly Software Solutions Inc
+ *
+ * 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.fireflyframework.eda.config;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.env.EnvironmentPostProcessor;
+import org.springframework.core.env.ConfigurableEnvironment;
+import org.springframework.core.env.MapPropertySource;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
+
+/**
+ * Environment post-processor that conditionally excludes Spring Boot's
+ * RabbitMQ and Kafka auto-configurations when the corresponding Firefly EDA
+ * transports are not enabled.
+ *
+ * <p>This prevents Spring Boot from auto-creating connection factories and
+ * health indicators for messaging systems that the application does not use,
+ * avoiding startup errors like "Rabbit health check failed - Connection refused".
+ *
+ * <p><strong>Behavior:</strong>
+ * <ul>
+ *   <li>If neither {@code firefly.eda.publishers.rabbitmq.default.enabled} nor
+ *       {@code firefly.eda.consumer.rabbitmq.default.enabled} is {@code true},
+ *       and {@code spring.rabbitmq.host} is not explicitly set,
+ *       then {@code RabbitAutoConfiguration} is excluded.</li>
+ *   <li>If neither {@code firefly.eda.publishers.kafka.default.enabled} nor
+ *       {@code firefly.eda.consumer.kafka.default.enabled} is {@code true},
+ *       and {@code spring.kafka.bootstrap-servers} is not explicitly set,
+ *       then {@code KafkaAutoConfiguration} is excluded.</li>
+ * </ul>
+ *
+ * <p>Any existing {@code spring.autoconfigure.exclude} entries are preserved.
+ */
+public class FireflyEdaEnvironmentPostProcessor implements EnvironmentPostProcessor {
+
+    private static final String EXCLUDE_PROPERTY = "spring.autoconfigure.exclude";
+    private static final String RABBIT_AUTO_CONFIG = "org.springframework.boot.autoconfigure.amqp.RabbitAutoConfiguration";
+    private static final String KAFKA_AUTO_CONFIG = "org.springframework.boot.autoconfigure.kafka.KafkaAutoConfiguration";
+
+    @Override
+    public void postProcessEnvironment(ConfigurableEnvironment environment, SpringApplication application) {
+        List<String> excludes = new ArrayList<>();
+
+        if (shouldExcludeRabbit(environment)) {
+            excludes.add(RABBIT_AUTO_CONFIG);
+        }
+
+        if (shouldExcludeKafka(environment)) {
+            excludes.add(KAFKA_AUTO_CONFIG);
+        }
+
+        if (!excludes.isEmpty()) {
+            applyExcludes(environment, excludes);
+        }
+    }
+
+    private boolean shouldExcludeRabbit(ConfigurableEnvironment env) {
+        // Respect explicit Spring Boot native configuration
+        if (env.containsProperty("spring.rabbitmq.host")) {
+            return false;
+        }
+
+        boolean publisherEnabled = env.getProperty(
+                "firefly.eda.publishers.rabbitmq.default.enabled", Boolean.class, false);
+        boolean consumerEnabled = env.getProperty(
+                "firefly.eda.consumer.rabbitmq.default.enabled", Boolean.class, false);
+
+        return !publisherEnabled && !consumerEnabled;
+    }
+
+    private boolean shouldExcludeKafka(ConfigurableEnvironment env) {
+        // Respect explicit Spring Boot native configuration
+        if (env.containsProperty("spring.kafka.bootstrap-servers")) {
+            return false;
+        }
+
+        boolean publisherEnabled = env.getProperty(
+                "firefly.eda.publishers.kafka.default.enabled", Boolean.class, false);
+        boolean consumerEnabled = env.getProperty(
+                "firefly.eda.consumer.kafka.default.enabled", Boolean.class, false);
+
+        return !publisherEnabled && !consumerEnabled;
+    }
+
+    private void applyExcludes(ConfigurableEnvironment environment, List<String> newExcludes) {
+        // Read existing excludes to preserve them
+        String existing = environment.getProperty(EXCLUDE_PROPERTY, "");
+        List<String> allExcludes = new ArrayList<>();
+
+        if (!existing.isEmpty()) {
+            allExcludes.addAll(
+                    Arrays.stream(existing.split(","))
+                            .map(String::trim)
+                            .filter(s -> !s.isEmpty())
+                            .collect(Collectors.toList()));
+        }
+
+        // Add new excludes (avoiding duplicates)
+        for (String exclude : newExcludes) {
+            if (!allExcludes.contains(exclude)) {
+                allExcludes.add(exclude);
+            }
+        }
+
+        Map<String, Object> props = new HashMap<>();
+        props.put(EXCLUDE_PROPERTY, String.join(",", allExcludes));
+
+        environment.getPropertySources().addFirst(
+                new MapPropertySource("fireflyEdaAutoConfigExcludes", props));
+    }
+}

src/main/resources/META-INF/spring.factories

@@ -0,0 +1,2 @@
+org.springframework.boot.env.EnvironmentPostProcessor=\
+  org.fireflyframework.eda.config.FireflyEdaEnvironmentPostProcessor