Sample build.gradle template for Gradle Vaadin Plugin projects

build.gradle

/**
 * Applies the latest version of the Vaadin plugin to the project. If a specific
 * version of the plugin is wanted,  append "?version=0.7" to the url.
 */
apply from: 'http://plugins.jasoft.fi/vaadin.plugin'

/**
 * The vaadin extension configures different aspects of how the vaadin plugin behaves
 * in the project.
 */
vaadin {

  /**
   * Defines what version of Vaadin the plugin should use. The version can be
   * defined as a specific number (7.1.13) or as a string where '+' means the latest.
   *
   * This version is used by the plugin to automatically add the right Vaadin dependencies
   * to the project.
   *
   * The default is the latest version of Vaadin 7.
   */
  version '7.1.+'

  /**
   * The path to the GWT module (Widgetset) gwt.xml file defined as a classname.
   *
   * This parameter is used by the updateWidgetset task to automatically generate the xml
   * file on demand.
   *
   * By default the widgetset is defined as null meaning the application is a server side
   * only project without a widgetset.
   */
  widgetset 'com.example.MyExampleWidgetset'

  /**
   * The classname to the Widgetset generator class that can configure different kinds of
   * lazy loading optimizations to the Vaadin application.
   *
   * By default this is null which means that the Widgetset generator provided by Vaadin
   * is used.
   *
   * Using this property requires that the widgetset is not null and that manageWidgetset
   * is turned on.
   */
  widgetsetGenerator 'com.example.MyExampleWidgetsetGenerator'

  /**
   * Defines if the application should run in debug mode.
   *
   * Debug mode affects many aspects of the Vaadin application itself.
   *
   * Some of the aspects are, but not limited to:
   *  - Debug Window is available when appending &debug to application url
   *  - Java debugger is attached to Java process when running application with vaadinRun task
   *  - Java assertions are turned on with the -ea parameter
   *  - Application is automatically launced with the &debug parameter when running the
   *    application with the vaadinRun task
   *  - Vaadin Application shows communication and other errors with bright red popops
   *
   * By default debug mode is turned on to ease development. For production it is recommended
   * that debug mode is turned off.
   */
  debug true

  /**
   * The port of the Java debugger attached to the Java process when launching the application
   * with the vaadinRun task.
   */
  debugPort 8000

  /**
   * The Vaadin Profiler helps profile rendering speeds in client side Vaadin applications.
   *
   * By defualt the profiler is turned on.
   *
   * This setting only works if manageWidgetset is set to true and widgetset is not null.
   */
  profiler true

  /**
   * Should the plugin manage the widgetset by automatically generating a gwt.xml file.
   *
   * This flag controls the following aspects of the widgetset handling:
   * - Creates the gwt.xml file on demand whenever the widgetset needs updating
   * - Allows the plugin to scan the classpath for Vaadin Add-ons and include any addon widgetsets
   *   into the project.
   * - Adds necessary linkers for handling SCSS in client side applications
   * - Configures many properties defined in build.gradle.
   *
   * By default manageWidgetset is turned on.
   */
  manageWidgetset true

  /**
   * Should the plugin add the required repositories for fetching the vaadin dependencies.
   *
   * By default this is turned on so no external repositories need to be manually defined.
   */
  manageRepositories = true

  /**
   * Should the plugin add the required Vaadin depenendencies to the project automatically.
   *
   * By defualt this is turned on so no external dependencies need to be added before creating a Vaadin application.
   */
  manageDependencies true

  /**
   * The port on which the embedded Jetty server should run when running the vaadinRun task.
   */
  serverPort 8080

  /**
   * Extra JVM arguments passed to the Java process when running the widgetset or vaadinRun tasks.
   */
  jvmArgs()

  /**
   * Should Vaadin Push be enabled.
   *
   * By default Vaadin's Push implementation is not enabled as most applications will never need push.
   * Turning on push adds the necessary Vaadin push dependency (if manageDependencies is enabled) for using Vaadin's
   * push implementation in the Vaadin application.
   */
  push false

  /**
   * Defines the main source set to use when generating new classes.
   *
   * By default this is in src/main/java
   */
  mainSourceSet sourceSets.main.java

  /**
   * Configurations for the GWT compiler used by Vaadin to compiler the browser implementation
   */
  gwt {
    
    /**
     * The compilation style of the Javascript produced by the GWT compiler
     *
     * Possible options are OBF[USCATED], PRETTY, or DETAILED. Default is OBF
     */
    style "OBF" 

    /**
     * Level of optimizations done by the GWT Compiler. 
     *
     * Possible values ranges from 0 to 9 where 0 is no optimization and 9 is maximum level of optimizations. Default is 0.
     */
    optimize 0
    
    /**
     * Is client side logging enabled for the project. Default is true.
     */
    logging true
    
    /**
     * The level of logging in client side code. 
     *
     * Possible values are ERROR, WARN, INFO, TRACE, DEBUG, SPAM, or ALL. Default is INFO
     */
    logLevel "INFO"
    
    /**
     * The amount of workers that should compile the widgetset simultaniously.
     *
     * By default this is the amount of CPU cores that are available.
     */
    localWorkers 1
    
    /**
     * Draft compile allows for faster recompiles of the widgetset
     *
     * By default this is off.
     */
    draftCompile true
    
    /**
     * Strict compiling fails the compilation on any error and provides better error messages.
     *
     * By defailt this is off.
     */
    strict true
    
    /**
     * The browsers that the Vaadin application should support
     *
     * By default this is null which signifies all supported browsers 
     */
    userAgent 'ie8,ie9,ie10,gecko1_8,safari,opera'
    
    /**
     * Extra JVM arguments passed to the GWT compiler
     */
    jvmArgs()
    
    /**
     * Extra GWT compiler arguments
     */
    extraArgs ''
    
    /**
     * Paths where the GWT Compiler should search for client side code.
     * 
     * By default the compiler will search in the 'client' and 'shared' packages.
     */
    sourcePaths('client', 'shared')
    
    /**
     * Should all GWT Permutations be collapsed into one permutation for 
     * larger filesize but faster compile time.
     *
     * Default is off.
     */
    collapsePermutations true
    
    /**
     * Extra GWT modules that should be added to the widgetset.
     */
    extraInherits()
  }

  /**
   * Configurations for running Developement Mode
   */
  devmode {

    /**
     * Should the Jetty server included with Development Mode be used. 
     *
     * Usually you don't want this, by default off.
     */
    noserver false
    
    /**
     * Should the experimental "Super" Development Mode feature be enabled. 
     * Might be good for javascript debugging, but usually not worth it.
     *
     * By default off.
     */
    superDevMode false
    
    /**
     * To what address should the development mode be attached.
     *
     * By default attaches itself to localhost.
     */
    bindAddress '0.0.0.0'
    
    /**
     * On what port should the development mode be run on. Default is 9997.
     */
    codeServerPort 9997
  }

  /**
   * Configrations for Vaadin addon projects
   */
  addon {

    /**
     * The name of the author of the project
     */ 
    author ''
    
    /**
     * The licence of the project.
     */
    license 'Apache 2.0'
    
    /**
     * The title of the project as it will be shown in the Vaadin Directory.
     */
    title 'My Project'
  }

  /**
   * Configurations for enabling Testbench unit testing
   */
  testbench {

    /**
     * Should testbench testing be enabled for the the project. 
     * 
     * Remember that by turning this to true you agree to the licence terms
     * required by Vaadin Testbench. Vaadin Testbench is a commercial product
     * developed by Vaadin.
     *
     * By default false.
     */
    enabled false
    
    /**
     * The version of testbench you want to use. The version will automatically be
     * included as a dependency to the project if manageDependencies is true.
     *
     * By default the latest version 3 release.
     */
    version '3.+'
    
    /**
     * When the Testbench unit test is run should the vaadin application be started
     * with the embedded Jetty server (same as running the application with vaadinRun).
     *
     * When this is set to true the server is started when the test is started and shutdown
     * when the test ends.
     *
     * By default this is true.
     */
    runApplication true
    
    /**
     * Defines configuration options for running a Testbench hub
     */
    hub {
      
      /**
       * Should the hub be enabled and started when running tests.
       *
       * By default this is false since normally you want to have a central hub running somewhere
       * on the intranet which all test runners contacts.
       */
      enabled false
      
      /**
       * The host on which the hub should run on. By default localhost.
       */
      host 'localhost'
      
      /**
       * The port on which the hub should be run on. By default 4444.
       */
      port 4444
    }
    
    /**
     * Defines configuration options for running a Tesbench node.
     */ 
    node {
      
      /**
       * Should the node be enabled and started when running tests
       * 
       * By default this is false since normally you want to have nodes already running on the intranet
       * which the hub can contact without needing to start the node every time a test is run.
       */
      enabled false
      
      /**
       * The host on which the node runs. By default localhost.
       */
      host 'localhost'
      
      /**
       * The port on which the node is run. By default 4445.
       */
      port 4445
      
      /**
       * The URL of the hub where the node should register itself.
       *
       * By default the hub running on localhost is assumed.
       */
      hub 'http://localhost:4444/grid/register'
      
      /**
       * Which browsers does the node support.
       *
       * An example of a browser configuration could look like this:
       *
       * browsers([
       *     [ browserName: 'firefox', version: 3.6, maxInstances: 5, platform: 'LINUX' ], 
       *     [ browserName: 'chrome', version: 22, maxInstances: 1, platform: 'WINDOWS' ]
       * ])
       *
       * See http://code.google.com/p/selenium/wiki/Grid2 for more information about available browsers and
       * settings. The browser setting will be stringingified into the -browser parameter for the hub.
       *
       * By default no browsers are configured.
       */
      browsers()      
    }
  }

  /**
   * Configurations for enabled JRebel with the project
   */
  jrebel {
    
    /**
     * Should using JRebel be enabled.
     *
     * If you enable the JRebel intergration you agree to the terms and conditions set by
     * ZeroTurnaround (http://zeroturnaround.com) and you will need a valid licence for the product.
     */
    enabled false
    
    /**
     * The absolute file path of the jrebel.jar provided by the JRebel installation package. Required 
     * for JRebel to work.
     */
    location ''
  }

  /**
   * Misc. plugin configurations
   */
  plugin {
    
    /**
     * Should the server started by the vaadinRun or devmode tasks be terminated by Enter key.
     *
     * By default the servers can be terminated with the Enter key.
     */
    terminateOnEnter true
    
    /**
     * Should all logs be piped to the console or logged to file under the build directory.
     *
     * By default all logging are done to file.
     */
    logToConsole false
    
    /**
     * When launching the application with vaadinRun should the application automatically be 
     * launched in the default browser.
     *
     * By default the application is opened in the browser when the server is run.
     */
    openInBrowser true   
  }

}

Hi looks like the location of the plugin changed? This does not work:
apply from: 'http://plugins.jasoft.fi/vaadin.plugin

You might want to try this:

plugins {
  id "fi.jasoft.plugin.vaadin" version "1.1.8"
}