conf := ldapsync.LDAPSyncConfig {
    ...
}
result, err := ldapsync.Do(conf)

port := "389"
conf := ldapsync.LDAPSyncConfig{
    BaseDNs: []string{"dc=example,dc=org"},
    ServerConfig: ldapsync.LDAPConfig{
        Server:                 "localhost", //LDAP server

        // set to false if server supports anonymous query,
        // in which case the SyncUserName and the SyncUserPassword
        // are not necessary
        RequiresAuthentication: true,

        SyncUserName:           "cn=admin,dc=example,dc=org",
        SyncUserPassword:       "secret_admin_password",

        //LDAP port, default 389, if not set
        Port:                   &port,
    },
    GroupFilter: ldapsync.LDAPFilter{
        // This is how we identify groups in the LDAP tree. In this case
        // it says if the LDAP entity's "objectClass" attribute contains
        // value "posixGroup" then the entry is a "group"
        Filters: []ldapsync.FilterExpression{
            {
                Name:  "objectClass",
                Value: "posixGroup",
            },
        },
    },
    UserFilter: ldapsync.LDAPFilter{
        //This is how we identify users in the LDAP tree. In this case,
        // it says if the LDAP entity's "objectClass" attribute has a
        // value "inetOrgPerson" then the entry is a "user"
        Filters: []ldapsync.FilterExpression{
            {
                Name:  "objectClass",
                Value: "inetOrgPerson",
            },
        },
    },

    GroupMembership: ldapsync.GroupMembershipAssociator{
        //This is how we map users to groups. In this example,
        // it is when a user's "uid" is contained in a group's
        // "memberUid" attribute
        UserAttribute:  "uid",
        GroupAttribute: "memberUid",
    },
}

//sync against the LDAP server
 result, err := ldapsync.LDAP(conf)

 if err != nil {
    log.Fatal(err)
 }

 fmt.Printf("\nGroups:\n %v\n", result.GetGroups())
 fmt.Printf("\nUsers:\n %v", result.GetUsers())

//check membership
user := "cn=admin,dc=example,dc=org"
group := "cn=ServerAdmins,dc=example,dc=org"
 fmt.Printf("\n It is %v that user %s is a memeber of group %s",
   result.IsMember(user, group), user, group)