ping: [PATCH proxmox{-backup,-mail-forward} 0/5] forward mails through notification worker; PDM compatibility

["Lukas Wagner" <l.wagner@proxmox.com>]

On Thu Apr 9, 2026 at 3:27 PM CEST, Lukas Wagner wrote:
> Forwarding through the worker has a couple of benefits:
>   - We don't need to bump proxmx-mail-forwarder for changes in proxmox-notify (at
>     least as soon as PVE uses a similar approach as well)
>   - any notification state (history, tokens) becomes easier to reason
>     about if there is only one process touching it
>   - we can move the Context trait implementations from proxmox_notify to the
>     actual product code again
>
> Technically we'd need a versioned break between proxmox-backup and
> proxmox-mail-forward, due to the 'mail-forwarder' feature that was not enabled in PBS
> before, as well as the changed spool directory. If proxmox-mail-forward is
> updated without updating proxmox-backup, forwarding the mail would fail due to
>
>   - /var/lib/proxmox-backup/notifications/queue not existing
>   - proxmox-backup not being able to deserialize notifications of the 'Forwarded Mail' kind
>
> I don't think there is a way around this breakage, but we *could* defuse it by:
>
>   - keep sending the old way (by directly calling into proxmox_notify)
>   - but still change PBS to enable the 'mail-forwarder' feature and use the new spool-dir path
>   - at some point in the future we switch proxmox-mail-forward to use the
>     queue-based/worker approach, making it less likely that someone still
>     holds back a proxmox-backup update, which would break forwarding
>
> I'll leave this decision to the PBS maintainers, just tell me which approach is
> preferrable, then I'll adapt the series if needed.
>

gentle ping for the PBS parts - not super important, but Arthur's
XOAUTH2 series relies on the changed directory structure in
/var/lib/proxmox-backup/notifications