prep LXC script searches /cdrom as apt repo

[Nicolas Formichella]

Running `openstack-ansible setup-hosts.yml` (git rev c3142a91a397d039b44fc02fbae3d364075cdc47) on (both dev and target are) Ubuntu 22.04 Jammy fails at `Ensure that the LXC cache has been prepared`

```
fatal: [infra1]: FAILED! => {"ansible_job_id": "j433753969570.43784", "attempts": 1, "changed": true, "cmd": "chroot /var/lib/machines/ubuntu-22-amd64 /opt/cache-prep-commands.sh > /var/log/lxc-cache-prep-commands.log 2>&1", "delta": "0:00:00.059611", "end": "2024-01-08 15:07:38.717758", "finished": 1, "msg": "non-zero return code", "rc": 100, "results_file": "/root/.ansible_async/j433753969570.43784", "start": "2024-01-08 15:07:38.658147", "started": 1, "stderr": "", "stderr_lines": [], "stdout": "", "stdout_lines": []}
```

[Dmitriy Rabotyagov (noonedeadpunk)]

Hi Nicolas,

Thanks for reporting that.

Can you kindly also supply a content of /etc/apt/sources.list from the infra1 node? Since LXC containers just inherit node repositories settings by default: https://opendev.org/openstack/openstack-ansible-lxc_hosts/src/branch/master/vars/debian.yml#L23-L31

[Nicolas Formichella (signed)]

It used to do, and removing the offending line fixed the issue, thanks for the lead

[Dmitriy Rabotyagov (noonedeadpunk)]

I'm actually not sure if this bug is invalid. I feel like it might be wise to filter out cdrom from potential sources on container, or maybe even from hosts.