Now all your LoginModules that need to get the current ExoContainer must extends org.exoplatform.services.security.jaas.AbstractLoginModule. You just need to call the method getContainer() to get the current ExoContainer.
The class org.exoplatform.services.security.jaas.AbstractLoginModule supports 2 login module options which are portalContainerName and realmName, to allow you to indicate the realm name and the portal container name, if you want to change the default value.