Add log message if Docker Compose services are already running

Closes gh-38398

Author: mhalbritter

spring-boot-project/spring-boot-docker-compose/src/main/java/org/springframework/boot/docker/compose/lifecycle/DockerComposeLifecycleManager.java

@@ -118,14 +118,19 @@ void start() {
 		Stop stop = this.properties.getStop();
 		Wait wait = this.properties.getReadiness().getWait();
 		List<RunningService> runningServices = dockerCompose.getRunningServices();
-		if (lifecycleManagement.shouldStart() && runningServices.isEmpty()) {
-			start.getCommand().applyTo(dockerCompose, start.getLogLevel());
-			runningServices = dockerCompose.getRunningServices();
-			if (wait == Wait.ONLY_IF_STARTED) {
-				wait = Wait.ALWAYS;
+		if (lifecycleManagement.shouldStart()) {
+			if (runningServices.isEmpty()) {
+				start.getCommand().applyTo(dockerCompose, start.getLogLevel());
+				runningServices = dockerCompose.getRunningServices();
+				if (wait == Wait.ONLY_IF_STARTED) {
+					wait = Wait.ALWAYS;
+				}
+				if (lifecycleManagement.shouldStop()) {
+					this.shutdownHandlers.add(() -> stop.getCommand().applyTo(dockerCompose, stop.getTimeout()));
+				}
 			}
-			if (lifecycleManagement.shouldStop()) {
-				this.shutdownHandlers.add(() -> stop.getCommand().applyTo(dockerCompose, stop.getTimeout()));
+			else {
+				logger.info("There are already Docker Compose services running, skipping startup");
 			}
 		}
 		List<RunningService> relevantServices = new ArrayList<>(runningServices);

spring-boot-project/spring-boot-docker-compose/src/test/java/org/springframework/boot/docker/compose/lifecycle/DockerComposeLifecycleManagerTests.java

@@ -29,6 +29,7 @@
 
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
 import org.junit.jupiter.api.io.TempDir;
 
 import org.springframework.aot.AotDetector;
@@ -38,6 +39,8 @@
 import org.springframework.boot.docker.compose.core.DockerComposeFile;
 import org.springframework.boot.docker.compose.core.RunningService;
 import org.springframework.boot.docker.compose.lifecycle.DockerComposeProperties.Readiness.Wait;
+import org.springframework.boot.test.system.CapturedOutput;
+import org.springframework.boot.test.system.OutputCaptureExtension;
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.ApplicationListener;
 import org.springframework.context.support.GenericApplicationContext;
@@ -59,6 +62,7 @@
  * @author Phillip Webb
  * @author Scott Frederick
  */
+@ExtendWith(OutputCaptureExtension.class)
 class DockerComposeLifecycleManagerTests {
 
 	@TempDir
@@ -365,6 +369,21 @@ void startPublishesEvent() {
 		assertThat(event.getRunningServices()).isEqualTo(this.runningServices);
 	}
 
+	@Test
+	void shouldLogIfServicesAreAlreadyRunning(CapturedOutput output) {
+		setUpRunningServices();
+		this.lifecycleManager.start();
+		assertThat(output).contains("There are already Docker Compose services running, skipping startup");
+	}
+
+	@Test
+	void shouldNotLogIfThereAreNoServicesRunning(CapturedOutput output) {
+		given(this.dockerCompose.hasDefinedServices()).willReturn(true);
+		given(this.dockerCompose.getRunningServices()).willReturn(Collections.emptyList());
+		this.lifecycleManager.start();
+		assertThat(output).doesNotContain("There are already Docker Compose services running, skipping startup");
+	}
+
 	private void setUpRunningServices() {
 		setUpRunningServices(true);
 	}