A groovy script returning a list of users' groups from LDAP server using JNDI API

listLdapGroupsJNDI.groovy

import javax.naming.directory.*

MYDOM = 'example.com'

// convert DNS domain to a LDAP notation
dns2ldap = {dom ->
  'DC=' + dom.split(/\./).join(',DC=')
}

// base OU for our search
GRP_OU = 'OU=users,' + dns2ldap(MYDOM)

/* make a new InitialDirContext for LDAP search
 * an awful mess caused only by three not-so-groovy things:
 * 1. InitialDirContext's constructor wants Hashtable instead of HashMap as a parameter
 * 2. GStrings in the arguments of this constructor should be explicitly converted to java Strings
 * 3. groovy's HashMap square brackets constructor doesn't support dots or brackets in keys
 */
mkCtx = {param = [:] ->
  new InitialDirContext(
    (Hashtable)param.collect {k, v ->
      [InitialDirContext[k], v.toString()]
    }.collectEntries()
  )
}

mkCtx(PROVIDER_URL: "ldap://ldap.$MYDOM",
  INITIAL_CONTEXT_FACTORY: 'com.sun.jndi.ldap.LdapCtxFactory',
  SECURITY_AUTHENTICATION: 'simple',
  SECURITY_PRINCIPAL: "CN=dummy,$GRP_OU",
  SECURITY_CREDENTIALS: 'aTerriblyStup1dPassW0rd',
).search(
  GRP_OU, '(objectclass=group)', new SearchControls([searchScope: SearchControls.SUBTREE_SCOPE])
).collect {
  it.attributes['cn']
}.sort().join('\n')

def response = (
mkCtx(PROVIDER_URL: "ldap://ldap.$MYDOM",
INITIAL_CONTEXT_FACTORY: 'com.sun.jndi.ldap.LdapCtxFactory',
SECURITY_AUTHENTICATION: 'simple',
SECURITY_PRINCIPAL: "yourAdminUser",
SECURITY_CREDENTIALS: 'YourAdminUserPassword',
).search(
GRP_OU, '(objectclass=group)', new SearchControls([searchScope: SearchControls.SUBTREE_SCOPE])
).collect {
it.attributes['cn']
}
)
return response.sort().join('\n')

def group_list = []

for(i = 0; i < response.size(); i++){
response[i] = response[i].toString().replaceAll("cn:", "")
group_list.add(response[i])
}
server_list = group_list.unique()
return group_list.sort()