Configure logging for the Gretty Gradle Plugin using the SLF4J Logback configuration file (logback-test.xml) from the sample integration test source.

buildSrc/src/main/groovy/io/spring/gradle/convention/SpringSampleWarPlugin.groovy

@@ -18,6 +18,7 @@ package io.spring.gradle.convention
 import org.gradle.api.Project
 import org.gradle.api.Task
 import org.gradle.api.plugins.PluginManager
+import org.gradle.api.tasks.SourceSetContainer
 import org.gradle.api.tasks.testing.Test
 
 /**
@@ -40,12 +41,23 @@ class SpringSampleWarPlugin extends SpringSamplePlugin {
         pluginManager.apply("war")
         pluginManager.apply("org.gretty")
 
+        def resolvedLogbackConfigFile = new File(project.extensions.getByType(SourceSetContainer)
+            .findByName("integrationTest")?.resources?.filter {
+                "logback-test.xml".equals(it.name)
+            }?.singleFile?.absolutePath)
+
+        // println "Resolved logbackConfigFile [$resolvedLogbackConfigFile]"
+
         project.gretty {
             servletContainer = 'tomcat10'
             contextPath = '/'
             consoleLogEnabled = false
             fileLogEnabled = false
             loggingLevel = 'OFF'
+
+            if (resolvedLogbackConfigFile?.isFile()) {
+                logbackConfigFile = resolvedLogbackConfigFile
+            }
         }
 
         Task prepareAppServerForIntegrationTests = project.tasks.create('prepareAppServerForIntegrationTests') {