Agent based installation stuck on validating hosts in RHOCP 4

Issue

• The rendezvous is stuck waiting on validating the hosts.

• The agent service is reporting the following validation failure:

  {ID:hostname-valid Status:failure Message:Hostname WORKER0.example.com is forbidden, hostname should match pattern ^[a-z0-9][a-z0-9-]{0,62}(?:[.][a-z0-9-]{1,63})*$}