How to login to Atlas after kerberizing sandbox cluster?

[#1]

I have installed the HDP sandbox HDP-3.0.1.0 (3.0.1.0-187) using Docker and Kerberized the cluster. 

I can list the principles from the keytab file like this:

klist -kte /etc/security/keytabs/atlas.service.keytab 

 Which gives the following output:

Keytab name: FILE:/etc/security/keytabs/atlas.service.keytab
KVNO Timestamp           Principal
---- ------------------- ------------------------------------------------------
   7 12/04/2019 10:27:18 atlas/[email protected] (des-cbc-md5)
   7 12/04/2019 10:27:18 atlas/[email protected] (des3-cbc-sha1)
   7 12/04/2019 10:27:18 atlas/[email protected] (arcfour-hmac)
   7 12/04/2019 10:27:18 atlas/[email protected] (aes256-cts-hmac-sha1-96)
   7 12/04/2019 10:27:18 atlas/[email protected] (aes128-cts-hmac-sha1-96)

Please forgive my stupidity, but how can I now login to Atlas UI?

I've tried the following "usernames" all without avail:

- atlas

- atlas/sandbox-hdp.hortonworks.com

- atlas/sandbox-hdp.hortonworks.com/MYREALM.TLD (i can get a valid ticket using kinit using this one)

- admin

- raj_ops (i can login to Ambari with this one)

p.s. I've used several password combinations like "admin", "raj_ops", "bigdata", "[mykerberospass]"...

[#2 · Accepted solution]

@RobertCare 
Nothing stupid 🙂 The credentials are tricky and documented here the learning the Ropes of the HDP Sandbox

See  the below screenshots  the atlas user& password  is  holger_gov/holger_gov

Atlas user & Passowrd

Explanation

Hope that helps

[#3]

Hmm that's interesting. During the process I changed the admin user/pass in the Ambari admin and I restarted Atlas. However those credentials didn't work. 

I just tried holger_gov/holger_gov and that also did not work. Tried restarting again and then the combination I manually configured did work...

So I'm up and running again for the moment! Thanks.