Support embedded jar initialization scripts

Update the Maven and Gradle plugin to generate fully executable jar
files on Unix like machines. A launcher bash script is added to the
front of the jar file which handles execution.

The default execution script will either launch the application or
handle init.d service operations (start/stop/restart) depending on if
the application is executed directly, or via a symlink to init.d.

See gh-1117

spring-boot-tools/spring-boot-gradle-plugin/src/main/groovy/org/springframework/boot/gradle/SpringBootPluginExtension.groovy

@@ -16,6 +16,9 @@
 
 package org.springframework.boot.gradle
 
+import java.io.File;
+import java.util.Map;
+
 import org.springframework.boot.loader.tools.Layout
 import org.springframework.boot.loader.tools.Layouts
 
@@ -130,4 +133,21 @@ public class SpringBootPluginExtension {
 	 */
 	boolean applyExcludeRules = true;
 
+	/**
+	 * If a fully executable jar (for *nix machines) should be generated by prepending a
+	 * launch script to the jar.
+	 */
+	boolean executable = true;
+
+	/**
+	 * The embedded launch script to prepend to the front of the jar if it is fully
+	 * executable. If not specified the 'Spring Boot' default script will be used.
+	 */
+	File embeddedLaunchScript;
+
+	/**
+	 * Properties that should be expanded in the embedded launch script.
+	 */
+	Map<String,String> embeddedLaunchScriptProperties;
+
 }

spring-boot-tools/spring-boot-gradle-plugin/src/main/groovy/org/springframework/boot/gradle/repackage/RepackageTask.java

@@ -28,6 +28,8 @@ import org.gradle.api.Project;
 import org.gradle.api.tasks.TaskAction;
 import org.gradle.api.tasks.bundling.Jar;
 import org.springframework.boot.gradle.SpringBootPluginExtension;
+import org.springframework.boot.loader.tools.DefaultLaunchScript;
+import org.springframework.boot.loader.tools.LaunchScript;
 import org.springframework.boot.loader.tools.Repackager;
 import org.springframework.util.FileCopyUtils;
 
@@ -80,6 +82,10 @@ public class RepackageTask extends DefaultTask {
 		this.classifier = classifier;
 	}
 
+	void setOutputFile(File file) {
+		this.outputFile = file;
+	}
+
 	@TaskAction
 	public void repackage() {
 		Project project = getProject();
@@ -170,7 +176,8 @@ public class RepackageTask extends DefaultTask {
 			}
 			repackager.setBackupSource(this.extension.isBackupSource());
 			try {
-				repackager.repackage(file, this.libraries);
+				LaunchScript launchScript = getLaunchScript();
+				repackager.repackage(file, this.libraries, launchScript);
 			}
 			catch (IOException ex) {
 				throw new IllegalStateException(ex.getMessage(), ex);
@@ -201,6 +208,15 @@ public class RepackageTask extends DefaultTask {
 			getLogger().info("Setting mainClass: " + mainClass);
 			repackager.setMainClass(mainClass);
 		}
+
+		private LaunchScript getLaunchScript() throws IOException {
+			if (this.extension.isExecutable()) {
+				return new DefaultLaunchScript(this.extension.getEmbeddedLaunchScript(),
+						this.extension.getEmbeddedLaunchScriptProperties());
+			}
+			return null;
+		}
+
 	}
 
 	/**
@@ -228,10 +244,7 @@ public class RepackageTask extends DefaultTask {
 				}
 			}
 		}
-	}
 
-	void setOutputFile(File file) {
-		this.outputFile = file;
 	}
 
 }