How to include a Zip file inside a ShadowJar during Gradle build - jar

Question

I am providing below what I have at the moment.
In the example below, the Jar task produces a Jar with a Zip file ( artifact from another project ) inside it.
But, My ultimate aim is to produce an uber jar that will self contain it's dependencies. I came by Shadow plugin and it seems a clean solution.
I tried to tell my ShadowJar task to include the Zip file - but it doesn't work. See commented out ShadowJar section.
So, what I have now is to create the shadow jar but then producing another jar that includes the contents of shadow jar and the zip. I can see that this path is full of gotchas (I had to enforce the Manifest again) ....
Ideally I would think that there is an way to include a artifact from different configuration in Shadow Jar and it is my limitation of Gradle knowledge that is failing here.
buildscript {
repositories { jcenter() }
dependencies {
classpath 'com.github.jengelman.gradle.plugins:shadow:1.1.1'
}
}
apply plugin: 'java'
apply plugin: 'eclipse'
apply plugin: 'com.github.johnrengelman.shadow'
project.version = rootProject.ext.deployerVersion
// In this section you declare where to find the dependencies of your project
repositories {
// Use 'maven central' for resolving your dependencies.
// You can declare any Maven/Ivy/file repository here.
mavenCentral()
}
configurations {
pkg
}
// In this section you declare the dependencies for your production and test code
dependencies {
compile project(':Concenter.Foundation')
pkg project(path: ':Concenter.Platform', configuration: 'pkg')
// Declare the dependency for your favourite test framework you want to use in your tests.
// TestNG is also supported by the Gradle Test task. Just change the
// testCompile dependency to testCompile 'org.testng:testng:6.8.1' and add
// 'test.useTestNG()' to your build script.
testCompile 'junit:junit:4.11'
}
jar {
dependsOn ':Concenter.Platform:distZip'
manifest {
attributes(
'Main-Class': 'aqilco.concenter.deployer.Deployer',
)
}
from configurations.pkg
}
/*
shadowJar {
dependsOn ':Concenter.Platform:distZip'
manifest {
attributes(
'Main-Class': 'aqilco.concenter.deployer.Deployer',
)
}
from configurations.pkg
}
*/
task pkg(type: Jar) {
dependsOn ':Concenter.Platform:distZip'
dependsOn 'shadowJar'
archiveName = jar.baseName + "-" + jar.version + "-pkg." + jar.extension
from zipTree(shadowJar.archivePath)
from configurations.pkg
manifest {
attributes(
'Main-Class': 'aqilco.concenter.deployer.Deployer',
)
}
}