Gradle WAR overlay plugin

A plugin for gradle to provide functionality similar to the war overlay function in maven. This plugin is initially developed to support building CAS servers, but should work in other situations. This plugin enhances the Gradle WAR plugin.

Configuration

Import the plugin:

buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath "org.scaldingspoon.gradle:gradle-waroverlay-plugin:0.9.3"
    }
}
apply plugin: 'waroverlay'

Alternatively, import the plugin in one line:

apply from: "http://dl.bintray.com/scalding/generic/waroverlay.gradle"

Add the WAR dependency you want to overlay as a runtime dependency:

dependencies {
    runtime("org.jasig.cas:cas-server-webapp:3.5.2@war") {
        transitive = true // setting this to true calculates transitive dependencies for addition to the target WAR
    }
}

Most other configuration is handled like the regular Gradle WAR plugin. There is one added convention:

warOverlay {
    includeWarJars false // whether to include the jar files in the WAR. Default is false. If false, it might be useful to set transitive to `true` for the WAR dependency so its dependencies will be calculated and added
}

For a sample, see https://github.com/Unicon/unicon-cas-overlay/blob/CAS4/build.gradle

Troubleshooting

If you include any signed JARs in your WAR, you'll likely encounter signature verification errors at runtime. To get around this, exclude the signature files from inclusion in your WAR like this:

war {
    // ... whatever else you may need
    exclude "META-INF/*.RSA", "META-INF/*.SF", "META-INF/*.DSA"
}