WARN
[main-SendThread(zookeeper.example.com:2181):ZooKeeperSaslClient$ClientCallbackHandler@459] - 
Could not login: the client is being asked for a password, but the Zookeeper client code does 
not currently support obtaining a password from the user. Make sure that the client is 
configured to use a ticket cache (using the JAAS configuration setting 'useTicketCache=true)' 
and restart the client. If you still get this message after that, the TGT in the ticket cache 
has expired and must be manually refreshed. To do so, first determine if you are using a 
password or a keytab. If the former, run kinit in a Unix shell in the environment of the 
user who is running this Zookeeper client using the command 'kinit <princ>' 
(where <princ> is the name of the client's Kerberos principal). If the latter, 
do 'kinit -k -t <keytab> <princ>' (where <princ> is the name of the Kerberos principal, 
and <keytab> is the location of the keytab file). After manually refreshing your cache, 
restart this client. If you continue to see this message after manually refreshing your cache, 
ensure that your KDC host's clock is in sync with this host's clock.

[Krb5LoginModule] authentication failed 

CLIENT_JVMFLAGS="-Djava.security.auth.login.config=/home/forsberg/jaas.conf" zookeeper-client -server zookeeper.example.com:2181

Client {
   com.sun.security.auth.module.Krb5LoginModule required
   useTicketCache=true;
};