Redirecting from index.gsp

To redirect to an initial page from the index.gsp

1. Create a TagLib file
  grails-app\taglib\MyAppTagLib.groovy

2. Define a method that routes to your first page
  class MyAppTagLib {
    def redirectMainPage = {
      response.sendRedirect("${request.contextPath}/myController/welcomePage/")
    }
  }

3. Change your index.gsp to contain only:
  <g:redirectMainPage/>

Note: One advantage to this approach is that you have a coding opportunity over simply mapping the "/" url.

For example, if you want to provide features or data based on a specific user's login id.