Polish "Add network option for image building"

See gh-27486

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/docs/asciidoc/packaging-oci-image.adoc

@@ -163,6 +163,12 @@ Where `<options>` can contain:
 * `volume-opt=key=value` to specify key-value pairs consisting of an option name and its value
 |
 
+| `network` +
+(`spring-boot.build-image.network`)
+| The https://docs.docker.com/network/#network-drivers[network driver] the builder container will be configured to use.
+The value supplied will be passed unvalidated to Docker when creating the builder container.
+|
+
 | `cleanCache` +
 (`spring-boot.build-image.cleanCache`)
 | Whether to clean the cache before building.
@@ -177,13 +183,6 @@ Where `<options>` can contain:
 | Whether to publish the generated image to a Docker registry.
 | `false`
 
-| `network` +
-(`spring-boot.build-image.network`)
-| The network the build container will connect to. The value supplied for this option will be passed
-unvalidated as `HostConfig.NetworkMode` to the configuration which creates the build container,
-see https://docs.docker.com/engine/api/v1.41/#operation/ContainerCreate[Docker's engine API].
-Using this option is similar to running `docker build --network ...`.
-|
 |===
 
 NOTE: The plugin detects the target Java compatibility of the project using the compiler's plugin configuration or the `maven.compiler.target` property.

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/intTest/java/org/springframework/boot/maven/BuildImageTests.java

@@ -270,6 +270,17 @@ public class BuildImageTests extends AbstractArchiveIntegrationTests {
 				});
 	}
 
+	@TestTemplate
+	void whenBuildImageIsInvokedWithNetworkModeNone(MavenBuild mavenBuild) {
+		mavenBuild.project("build-image-network").goals("package")
+				.systemProperty("spring-boot.build-image.pullPolicy", "IF_NOT_PRESENT").execute((project) -> {
+					assertThat(buildLog(project)).contains("Building image")
+							.contains("docker.io/library/build-image-network:0.0.1.BUILD-SNAPSHOT")
+							.contains("Network status: curl failed").contains("Successfully built image");
+					removeImage("build-image-network", "0.0.1.BUILD-SNAPSHOT");
+				});
+	}
+
 	@TestTemplate
 	void whenBuildImageIsInvokedOnMultiModuleProjectWithPackageGoal(MavenBuild mavenBuild) {
 		mavenBuild.project("build-image-multi-module").goals("package")

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/intTest/projects/build-image-network/pom.xml

@@ -0,0 +1,35 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+		 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<groupId>org.springframework.boot.maven.it</groupId>
+	<artifactId>build-image-network</artifactId>
+	<version>0.0.1.BUILD-SNAPSHOT</version>
+	<properties>
+		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+		<maven.compiler.source>@java.version@</maven.compiler.source>
+		<maven.compiler.target>@java.version@</maven.compiler.target>
+	</properties>
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>@project.groupId@</groupId>
+				<artifactId>@project.artifactId@</artifactId>
+				<version>@project.version@</version>
+				<executions>
+					<execution>
+						<goals>
+							<goal>build-image</goal>
+						</goals>
+						<configuration>
+							<image>
+								<builder>projects.registry.vmware.com/springboot/spring-boot-cnb-builder:0.0.1</builder>
+								<network>none</network>
+							</image>
+						</configuration>
+					</execution>
+				</executions>
+			</plugin>
+		</plugins>
+	</build>
+</project>

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/intTest/projects/build-image-network/src/main/java/org/test/SampleApplication.java

@@ -0,0 +1,28 @@
+/*
+ * Copyright 2012-2020 the original author or authors.
+ *
+ * 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
+ *
+ *      https://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.test;
+
+public class SampleApplication {
+
+	public static void main(String[] args) throws Exception {
+		System.out.println("Launched");
+		synchronized(args) {
+			args.wait(); // Prevent exit"
+		}
+	}
+
+}