Kerberos principal and keytab generation of the same service from different hosts

[mehdibn]

For HA support of some components like spark-history, mapred-job-history, ranger-admin and livy, we need to generate a principal and keytab for the HA Proxy SPNGEGO authentication : HTTP/{{ ha_address | urlsplit("hostname") }}

As ha_address is the same, if the principal is generated by different hosts, the first keytabs generated will be not validated.

One of the possible solutions consists on creating an ansible hosts' group in order to create this principal one time and share it between all concerned hosts.