Add bindings option for image building

This commit adds configuration to the Maven and Gradle plugins to
allow a list of volume mount bindings to be provided to the image
building goal and task. This enables service bindings to be mounted
in the builder image that are recognized by buildpacks to support
custom certificates, build tool configuration, APM integration, and
other buildpack features.

Fixes gh-23518

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

@@ -168,6 +168,15 @@ public class BuildImageTests extends AbstractArchiveIntegrationTests {
 				});
 	}
 
+	@TestTemplate
+	void failsWithBindingContainingInvalidCertificate(MavenBuild mavenBuild) {
+		mavenBuild.project("build-image-bindings").goals("package")
+				.systemProperty("spring-boot.build-image.pullPolicy", "IF_NOT_PRESENT")
+				.executeAndFail((project) -> assertThat(buildLog(project)).contains("Building image")
+						.contains("failed to decode certificate")
+						.contains("/platform/bindings/ca-certificates/test.crt"));
+	}
+
 	@TestTemplate
 	void failsWhenPublishWithoutPublishRegistryConfigured(MavenBuild mavenBuild) {
 		mavenBuild.project("build-image").goals("package").systemProperty("spring-boot.build-image.publish", "true")

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/intTest/projects/build-image-bindings/bindings/ca-certificates/test.crt

@@ -0,0 +1 @@
+not a valid certificate

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/intTest/projects/build-image-bindings/bindings/ca-certificates/type

@@ -0,0 +1 @@
+ca-certificates

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

@@ -0,0 +1,36 @@
+<?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-bindings</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>
+								<bindings>
+									<binding>${basedir}/bindings/ca-certificates:/platform/bindings/ca-certificates</binding>
+								</bindings>
+							</image>
+						</configuration>
+					</execution>
+				</executions>
+			</plugin>
+		</plugins>
+	</build>
+</project>

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

@@ -0,0 +1,28 @@
+/*
+ * Copyright 2012-2021 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
+		}
+	}
+
+}