OSP, the downstream version of tripleo have to enforce some policies
for rhel version and subscribed channel.
This module hosts hoses requirements, so that we prevent update to
wrong rhel release or subscription to wrong channels.
Currently it only implements a basic check to the subscribed rhel
version.
This check has some fail-safe logic to avoid crashing the update on
temporary network issue when running subscription-manager.
We are avoiding the validation framework as this can be easily
disabled and we want this enforcement to be mandatory as this could
lead user to unsupported combination of OSP/RHEL.
For upstream that change is transparent as the tasks are skipped if
the ansible_distribution is not Red Hat.
For Red Hat, there will be a mechanism in THT to avoid the check
altogether, for instance for CI purposes.
For this first check (RHEL/OSP version), downstream patches will add
the required values in vars/redhat.yml.
Change-Id: I2d1ac92ee6ee8407fb156a2718f94ad3e9220bbe
e65996b878