Container hostname change breaks unattended_url for external host registration

[pablomh]

Problem

Commit 4ef4632 ("use shorter internal hostnames for the pulp containers")
changed the Foreman container hostname from {{ ansible_facts['fqdn'] }} to
{{ ansible_facts['hostname'] }}.local for all containers, including the
Foreman application containers.

Foreman derives the unattended_url setting from the container's internal
hostname. After this change, unattended_url becomes http://satellite.local
instead of https://satellite.example.com, causing the Host initial configuration template to generate callbacks to an unreachable hostname.

Symptoms

All hosts register successfully via subscription-manager (POST /rhsm/consumers
works), but fail at the host init phase with:

ERROR: Host [hostname] configured, but failed to report status to Foreman.

The generated /root/registration_host_init.sh contains:

curl https://satellite.local/unattended/built?token=...

which is unreachable from external hosts.

Impact

• All host registrations using the global registration template fail
  at the host init callback phase
• CI does not catch this because it does not test the full registration
  flow with host init template execution
• Workaround: hammer settings set --name unattended_url --value "https://$(hostname -f)"

[evgeni]

Can you try #491 please

[pablomh]

As soon as I applied the diff and redeployed to an environment running master and trying to register systems (and failing), it started to work, so LGTM :) Thanks!!