This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
The Datasources plugin is the only solution that I've heard of for this issue. If you've tried that and had problems, I would encourage you to write to the Grails mailing list. The author of that plugin is one of the most helpful people on that list.