If you want to run your Selenium (WebDriver) tests from Gradle you can do it like this:

1. Add Jetty plugin to build.gradle:

apply plugin: 'jetty'

2. Create a src/selenium/java folder in you project root.

3. Add a SourceSet to build.gradle:

sourceSets {
    selenium
}

4. Add Selenium dependencies to build.gradle:

seleniumCompile 'junit:junit:4.11'
seleniumCompile 'org.seleniumhq.selenium:selenium-java:2.30.0'

Add jettyDaemon and selenium tasks to build.gradle:

task jettyDaemon(type: org.gradle.api.plugins.jetty.JettyRun) {
    daemon = true
}

task selenium(type: Test, dependsOn: jettyDaemon) {
    testClassesDir = sourceSets.selenium.output.classesDir
    classpath = sourceSets.selenium.runtimeClasspath
}

5. If you are using Eclipse, add Selenium dependencies to the Eclipse classpath in build.gradle:

eclipse {
    classpath {
        plusConfigurations += configurations.seleniumCompile
    }
}

You can now place you Selenium tests in src/selenium/java and run:

gradle clean selenium