Pulp

On CentOS 7 / RHEL 7, since recent refactoring, the role pulp_redis fails to install the package "redis" unless EPEL7 was already added to the system by the user.

(Our molecule CI's CentOS 7 docker image does install EPEL7, so it is not catching this bug.)

There are 4 possible solutions:

1. Copy the EPEL tasks from pulp_common to pulp_redis
2. Refactor the tasks into a common dependency/included role "pulp_repos", that presumably accepts variables from dependant roles like pulp_redis and pulp_common.
3. Use the SCL instead, which is what the Katello / Satellite build team prefer.
4. Ask if the task system refactoring will eliminate the need for redis altogether (so #1 would be a temporary hack.)

#3 would be especially time-consuming to implement in-place upgrade logic due to: * This looks problematic to migrate the redis database because of on different /var path. * If were to clear the redis database instead, we'd need to finish all Pulp tasks 1st.

Katello is working around this by calling a separate EPEL role.