Add tests for Gradle examples used in plugin docs

Fixes gh-25468

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/docs/gradle/packaging/boot-build-image-builder.gradle

@@ -13,3 +13,10 @@ bootBuildImage {
 	runImage = "mine/java-cnb-run"
 }
 // end::builder[]
+
+task bootBuildImageBuilder {
+	doFirst {
+		println("builder=${tasks.bootBuildImage.builder}")
+		println("runImage=${tasks.bootBuildImage.runImage}")
+	}
+}

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/docs/gradle/packaging/boot-build-image-builder.gradle.kts

 import org.springframework.boot.gradle.tasks.bundling.BootJar
+import org.springframework.boot.gradle.tasks.bundling.BootBuildImage
 
 plugins {
 	java
@@ -15,3 +16,10 @@ tasks.getByName<BootBuildImage>("bootBuildImage") {
 	runImage = "mine/java-cnb-run"
 }
 // end::builder[]
+
+tasks.register("bootBuildImageBuilder") {
+	doFirst {
+		println("builder=${tasks.getByName<BootBuildImage>("bootBuildImage").builder}")
+		println("runImage=${tasks.getByName<BootBuildImage>("bootBuildImage").runImage}")
+	}
+}

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/docs/gradle/packaging/boot-build-image-docker-auth-token.gradle

@@ -16,3 +16,9 @@ bootBuildImage {
 	}
 }
 // end::docker-auth-token[]
+
+task bootBuildImageDocker {
+	doFirst {
+		println("token=${tasks.bootBuildImage.docker.builderRegistry.token}")
+	}
+}

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/docs/gradle/packaging/boot-build-image-docker-auth-token.gradle.kts

@@ -19,3 +19,9 @@ tasks.getByName<BootBuildImage>("bootBuildImage") {
 	}
 }
 // end::docker-auth-token[]
+
+tasks.register("bootBuildImageDocker") {
+	doFirst {
+		println("token=${tasks.getByName<BootBuildImage>("bootBuildImage").docker.builderRegistry.token}")
+	}
+}

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/docs/gradle/packaging/boot-build-image-docker-auth-user.gradle

@@ -19,3 +19,12 @@ bootBuildImage {
 	}
 }
 // end::docker-auth-user[]
+
+task bootBuildImageDocker {
+	doFirst {
+		println("username=${tasks.bootBuildImage.docker.builderRegistry.username}")
+		println("password=${tasks.bootBuildImage.docker.builderRegistry.password}")
+		println("url=${tasks.bootBuildImage.docker.builderRegistry.url}")
+		println("email=${tasks.bootBuildImage.docker.builderRegistry.email}")
+	}
+}

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/docs/gradle/packaging/boot-build-image-docker-auth-user.gradle.kts

@@ -22,3 +22,12 @@ tasks.getByName<BootBuildImage>("bootBuildImage") {
 	}
 }
 // end::docker-auth-user[]
+
+tasks.register("bootBuildImageDocker") {
+	doFirst {
+		println("username=${tasks.getByName<BootBuildImage>("bootBuildImage").docker.builderRegistry.username}")
+		println("password=${tasks.getByName<BootBuildImage>("bootBuildImage").docker.builderRegistry.password}")
+		println("url=${tasks.getByName<BootBuildImage>("bootBuildImage").docker.builderRegistry.url}")
+		println("email=${tasks.getByName<BootBuildImage>("bootBuildImage").docker.builderRegistry.email}")
+	}
+}

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/docs/gradle/packaging/boot-build-image-docker-host.gradle

@@ -16,3 +16,11 @@ bootBuildImage {
 	}
 }
 // end::docker-host[]
+
+task bootBuildImageDocker {
+	doFirst {
+		println("host=${tasks.bootBuildImage.docker.host}")
+		println("tlsVerify=${tasks.bootBuildImage.docker.tlsVerify}")
+		println("certPath=${tasks.bootBuildImage.docker.certPath}")
+	}
+}

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/docs/gradle/packaging/boot-build-image-docker-host.gradle.kts

@@ -14,8 +14,16 @@ tasks.getByName<BootJar>("bootJar") {
 tasks.getByName<BootBuildImage>("bootBuildImage") {
 	docker {
 		host = "tcp://192.168.99.100:2376"
-		tlsVerify = true
+		isTlsVerify = true
 		certPath = "/home/users/.minikube/certs"
 	}
 }
 // end::docker-host[]
+
+tasks.register("bootBuildImageDocker") {
+	doFirst {
+		println("host=${tasks.getByName<BootBuildImage>("bootBuildImage").docker.host}")
+		println("tlsVerify=${tasks.getByName<BootBuildImage>("bootBuildImage").docker.isTlsVerify}")
+		println("certPath=${tasks.getByName<BootBuildImage>("bootBuildImage").docker.certPath}")
+	}
+}

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/test/java/org/springframework/boot/gradle/docs/PackagingDocumentationTests.java

@@ -43,6 +43,7 @@ import static org.assertj.core.api.Assertions.assertThat;
  *
  * @author Andy Wilkinson
  * @author Jean-Baptiste Nizet
+ * @author Scott Frederick
  */
 @ExtendWith(GradleMultiDslExtension.class)
 class PackagingDocumentationTests {
@@ -221,14 +222,21 @@ class PackagingDocumentationTests {
 	}
 
 	@TestTemplate
-	void bootBuildImageWithCustomBuildpackJvmVersion() throws IOException {
+	void bootBuildImageWithBuilder() {
+		BuildResult result = this.gradleBuild.script("src/docs/gradle/packaging/boot-build-image-builder")
+				.build("bootBuildImageBuilder");
+		assertThat(result.getOutput()).contains("builder=mine/java-cnb-builder").contains("runImage=mine/java-cnb-run");
+	}
+
+	@TestTemplate
+	void bootBuildImageWithCustomBuildpackJvmVersion() {
 		BuildResult result = this.gradleBuild.script("src/docs/gradle/packaging/boot-build-image-env")
 				.build("bootBuildImageEnvironment");
 		assertThat(result.getOutput()).contains("BP_JVM_VERSION=8.*");
 	}
 
 	@TestTemplate
-	void bootBuildImageWithCustomProxySettings() throws IOException {
+	void bootBuildImageWithCustomProxySettings() {
 		BuildResult result = this.gradleBuild.script("src/docs/gradle/packaging/boot-build-image-env-proxy")
 				.build("bootBuildImageEnvironment");
 		assertThat(result.getOutput()).contains("HTTP_PROXY=http://proxy.example.com")
@@ -236,14 +244,37 @@ class PackagingDocumentationTests {
 	}
 
 	@TestTemplate
-	void bootBuildImageWithCustomImageName() throws IOException {
+	void bootBuildImageWithCustomImageName() {
 		BuildResult result = this.gradleBuild.script("src/docs/gradle/packaging/boot-build-image-name")
 				.build("bootBuildImageName");
 		assertThat(result.getOutput()).contains("example.com/library/" + this.gradleBuild.getProjectDir().getName());
 	}
 
 	@TestTemplate
-	void bootBuildImagePublish() throws IOException {
+	void bootBuildImageWithDockerHost() {
+		BuildResult result = this.gradleBuild.script("src/docs/gradle/packaging/boot-build-image-docker-host")
+				.build("bootBuildImageDocker");
+		assertThat(result.getOutput()).contains("host=tcp://192.168.99.100:2376").contains("tlsVerify=true")
+				.contains("certPath=/home/users/.minikube/certs");
+	}
+
+	@TestTemplate
+	void bootBuildImageWithDockerUserAuth() {
+		BuildResult result = this.gradleBuild.script("src/docs/gradle/packaging/boot-build-image-docker-auth-user")
+				.build("bootBuildImageDocker");
+		assertThat(result.getOutput()).contains("username=user").contains("password=secret")
+				.contains("url=https://docker.example.com/v1/").contains("email=user@example.com");
+	}
+
+	@TestTemplate
+	void bootBuildImageWithDockerTokenAuth() {
+		BuildResult result = this.gradleBuild.script("src/docs/gradle/packaging/boot-build-image-docker-auth-token")
+				.build("bootBuildImageDocker");
+		assertThat(result.getOutput()).contains("token=9cbaf023786cd7...");
+	}
+
+	@TestTemplate
+	void bootBuildImagePublish() {
 		BuildResult result = this.gradleBuild.script("src/docs/gradle/packaging/boot-build-image-publish")
 				.build("bootBuildImagePublish");
 		assertThat(result.getOutput()).contains("true");