Grails LDAP integration with Active Directory via spring-security-ldap2013-08-10
The spring-security-ldap has great documentation. I put together a working example (at least in my environment) to complement the docs. When I was tasked with integrating our grails apps with Active Directory I remember there being a scarcity of examples.. so I hope this code will save you some time in getting ldap working with Active Directory in your grails environment.
once you have your Active Directory configurations entered (grails-app/conf/Config.groovy), fire up your app and test it out by logging in via the login controller.
You may have to update MyUserDetailsContextMapper.groovy as my Active Directory environment may differ from yours. You may also want to update MyUserDetails.groovy to hold more or less info than my config.