You need to have a valid kerberos ticket before running any commands in a kerberized cluster - To get valid ticket you issue
or if you like to use a SPN keytab
kinit -kt keytab principal@REALM
Having that said I recommend you go over this great post that explains the delegation tokens in detail:
*** If you found this answer addressed your question, please take a moment to login and click the "accept" link on the answer.