Hi, I’ve asked this question in the gradle slack,...

# multiplatform

[GarouDan]

Hi,

I’ve asked this question in the gradle slack, but it looks like this is more pertinent to this channel.

I’m trying to use the <https://github.com/johnrengelman/shadow> plugin, to create fatJars.

I’ve already done the integration in my project but I’m seeing only a knows task. (I’m using gradle 5.3.1)

My current configuration is:

import com.github.jengelman.gradle.plugins.shadow.tasks.ShadowJar
...
plugins {
    kotlin("multiplatform")

    id("com.github.johnrengelman.shadow") version "5.0.0"
}
...
tasks.withType<ShadowJar> {
    baseName = "app"
    classifier = ""
    version = ""
}

With ./gradlew tasks I can se only a knows task

Shadow tasks
------------
knows - Do you know who knows?

and if I run ./gradlew shadowJar I receive an error like:

* What went wrong:
Task 'shadowJar' not found in root project 'my_project'.

Does someone have a working example with a kotlin mpp project and fatJars?

It looks like the shadowJar task is created only in the presence of the JavaPlugin and because I’m using Kotlin it is not being created.

Thanks in advance!

[ribesg]

I guess you can just create the task yourself

[GarouDan]

It looks like this could be a little difficult.

It looks like I would need to convert this task to .kts and handle with the internal implementations of this plugin.

https://github.com/johnrengelman/shadow/blob/5.0.0/src/main/groovy/com/github/jengelman/gradle/plugins/shadow/ShadowJavaPlugin.groovy#L41-L66

[Dominaezzz]

You don't have to to that.

[Dominaezzz]

Just change withType to create.

[Dominaezzz]

Add a name too lol.

[GarouDan]

I tried something like:

tasks.create("shadowJar", ShadowJar::class.java) {
	baseName = "my_project"
	classifier = ""
	version = ""
}

and after running the shadowJar a file named my_project.jar was created.

But when I tried to run java -jar my_project.jar I’ve received

no main manifest attribute, in my_project.jar

So I think it is still not a fat jar yet =/

If you have any clues, please kindly let me know

[GarouDan]

Inside the jar I only have:

META-INF/
META-INF/MANIFEST.MF

and inside the manifest:

Manifest-Version: 1.0

[Dominaezzz]

Maybe https://stackoverflow.com/questions/53141692/using-gradle-shadow-with-kotlin-multiplatform helps?

[GarouDan]

I tried this approach and the main class was pointed but the dependencies weren’t being loaded.

I was able to put this to work with something like:

tasks.withType<ShadowJar> {
	manifest {
		attributes.put("Main-Class", "com.example.ExampleKt")
	}

	val target = kotlin.targets.jvm("myTarget")
	from(target.compilations["main"].output)
	val runtimeClasspath = target.compilations["main"].compileDependencyFiles as Configuration
	configurations = mutableListOf(runtimeClasspath)
}

I still need to check some other options, but finally something working 😉