Build native images using GraalVM (#1165)

build.sbt

@@ -94,6 +94,7 @@ addCommandAlias("validateUniversal", "scripted universal/*")
 addCommandAlias("validateJar", "scripted jar/*")
 addCommandAlias("validateBash", "scripted bash/*")
 addCommandAlias("validateAsh", "scripted ash/*")
+addCommandAlias("validateGraalVMNativeImage", "scripted graalvm-native-image/*")
 addCommandAlias("validateRpm", "scripted rpm/*")
 addCommandAlias("validateDebian", "scripted debian/*")
 addCommandAlias("validateDocker", "scripted docker/*")

src/main/scala/com/typesafe/sbt/packager/graalvm-native-image/GraalVMNativeImageKeys.scala

@@ -0,0 +1,13 @@
+package com.typesafe.sbt
+package packager
+package graalvmnativeimage
+
+import sbt._
+
+/**
+  * GraalVM settings
+  */
+trait GraalVMNativeImageKeys {
+  val graalVMNativeImageOptions =
+    SettingKey[Seq[String]]("graalvm-native-image-options", "GraalVM native-image options")
+}

src/main/scala/com/typesafe/sbt/packager/graalvm-native-image/GraalVMNativeImagePlugin.scala

@@ -0,0 +1,56 @@
+package com.typesafe.sbt.packager.graalvmnativeimage
+
+import sbt._
+import sbt.Keys._
+import java.nio.charset.Charset
+
+import com.typesafe.sbt.packager.SettingsHelper
+import com.typesafe.sbt.packager.Keys._
+import com.typesafe.sbt.packager.linux._
+import com.typesafe.sbt.packager.Compat._
+import com.typesafe.sbt.packager.validation._
+
+/**
+  * Plugin to compile ahead-of-time native executables.
+  *
+  * @example Enable the plugin in the `build.sbt`
+  * {{{
+  *    enablePlugins(GraalVMNativeImagePlugin)
+  * }}}
+  */
+object GraalVMNativeImagePlugin extends AutoPlugin {
+
+  object autoImport extends GraalVMNativeImageKeys {
+    val GraalVMNativeImage: Configuration = config("graalvm-native-image")
+  }
+
+  private val GraalVMNativeImageCommand = "native-image"
+
+  import autoImport._
+
+  override def projectConfigurations: Seq[Configuration] = Seq(GraalVMNativeImage)
+
+  override lazy val projectSettings = Seq(
+    target in GraalVMNativeImage := target.value / "graalvm-native-image",
+    graalVMNativeImageOptions := Seq.empty,
+    packageBin in GraalVMNativeImage := {
+      val targetDirectory = (target in GraalVMNativeImage).value
+      targetDirectory.mkdirs()
+      val binaryName = name.value
+      val command = {
+        val nativeImageArguments = {
+          val className = (mainClass in Compile).value.getOrElse(sys.error("Could not find a main class."))
+          val classpathJars = Seq((packageBin in Compile).value) ++ (dependencyClasspath in Compile).value.map(_.data)
+          val classpath = classpathJars.mkString(":")
+          val extraOptions = graalVMNativeImageOptions.value
+          Seq("--class-path", classpath, s"-H:Name=$binaryName") ++ extraOptions ++ Seq(className)
+        }
+        Seq(GraalVMNativeImageCommand) ++ nativeImageArguments
+      }
+      sys.process.Process(command, targetDirectory) ! streams.value.log match {
+        case 0 => targetDirectory / binaryName
+        case x => sys.error(s"Failed to run $GraalVMNativeImageCommand, exit status: " + x)
+      }
+    }
+  )
+}

src/sbt-test/graalvm-native-image/simple-native-image/build.sbt

@@ -0,0 +1,5 @@
+enablePlugins(GraalVMNativeImagePlugin)
+
+name := "simple-test"
+
+version := "0.1.0"

src/sbt-test/graalvm-native-image/simple-native-image/project/plugins.sbt

@@ -0,0 +1 @@
+addSbtPlugin("com.typesafe.sbt" % "sbt-native-packager" % sys.props("project.version"))

src/sbt-test/graalvm-native-image/simple-native-image/src/main/scala/Main.scala

@@ -0,0 +1,5 @@
+object Main {
+  def main(args: Array[String]): Unit = {
+    println("Hello Graal")
+  }
+}

src/sbt-test/graalvm-native-image/simple-native-image/test

@@ -0,0 +1,3 @@
+# Generate the GraalVM native image
+> show graalvm-native-image:packageBin
+$ exec bash -c 'target/graalvm-native-image/simple-test | grep -q "Hello Graal"'

src/sphinx/formats/graalvm-native-image.rst

@@ -0,0 +1,45 @@
+.. _graalvm-native-image-plugin:
+
+GraalVM Native Image Plugin
+=============
+
+GraalVM's ``native-image`` compiles Java programs AOT (ahead-of-time) into native binaries.
+
+  https://www.graalvm.org/docs/reference-manual/aot-compilation/ documents the AOT compilation of GraalVM.
+
+Requirements
+------------
+
+You must have ``native-image`` of GraalVM in your ``PATH``.
+
+Build
+-----
+
+.. code-block:: bash
+
+  sbt 'show graalvm-native-image:packageBin'
+
+
+Required Settings
+~~~~~~~~~~~~~~~~~
+
+.. code-block:: scala
+
+  enablePlugins(GraalVMNativeImagePlugin)
+
+
+Settings
+--------
+
+Publishing Settings
+~~~~~~~~~~~~~~~~~~~
+
+  ``graalVMNativeImageOptions``
+    Extra options that will be passed to the ``native-image`` command. By default, this includes the name of the main class.
+
+Tasks
+-----
+The GraalVM Native Image plugin provides the following commands:
+
+  ``graalvm-native-image:packageBin``
+    Generates a native image using GraalVM.