I was using Active Directory. Here are the values I eventually ended up using in my SecurityConfig.groovy class:
useLdap = true
ldapServer = ‘ldap://myADserver:389′
ldapManagerDn = ‘mydomain\\myuser’
ldapManagerPassword = ‘myPrivatePasswd’
ldapSearchBase = ‘OU=Someplace,DC=corp,DC=myCompany,DC=com’
ldapSearchFilter = ‘(sAMAccountName={0})’
ldapGroupSearchBase = ‘OU=Users,DC=corp,DC=myCompany,DC=com’
ldapGroupSearchFilter = ‘(member={0})’
ldapUsePassword = false

I never got the ldapGroup query to return any values, but that may be because my company does not use them that way. Instead, there was a “memberOf” attribute in the LDAP entry for each user. (I don’t know if this is a standard, a best practice or just what my company uses).

To set breakpoints in spring code, one must first download the appropriate sources jars and link to them in STS. I downloaded the jars (see below) and put them in my c:\grails-1.2.2\lib folder.

For the acegi plugin sources, I downloaded the plugin as a zip and put it in c:\grails-plugins.

To link to them, one has to know the class names of the relevant Spring classes.

Jar files:
spring-security-core-2.0.4-sources.jar
spring-ldap-1.2.1-sources.jar

Relevant classes & methods:
org.springframework.security…

…ldap.SpringSecurityLdapTemplate.searchForSingleEntry()

…ldap.SpringSecurityLdapTemplate.searchForSingleAttributeValues()

…providers.ldap.authenticator.BindAuthenticator.bindWithDn()

…userdetails.ldap.LdapUserDetailsMapper.mapUserFromContext()

org.springframework.ldap.core.LdapTemplate.search()

And from the acegi plugin zip:
grails-acegi-0.5.3.zip

org.codehaus.groovy.grails.plugins.springsecurity…

…GrailsDaoImpl.loadUserByUserName()

…ldap.GrailsUserDetailsMapper.mapUserFromContext()

I hope this helps somebody get started debugging using LDAP with the grails-acegi plugin.

I think the parameters I am using in SecurityConfig.groovy are wrong, but I cannot debug them without visibility.

I would love to set breakpoints and walk through the spring code, but I cannot figure out how to do this using STS. I can hit breakpoints in my code and select acegi plugin classes, but not in spring code (e.g. org.springframework.security.providers.ldap.authenticator.BindAuthenticator.java).