Re: [PATCH proxmox-backup v4 23/24] notifications: Add OAuth2 section to SMTP target docs

[Arthur Bied-Charreton <a.bied-charreton@proxmox.com>]

On Fri, Apr 24, 2026 at 10:18:38AM +0200, Shannon Sterz wrote:
> On Fri Apr 24, 2026 at 9:59 AM CEST, Arthur Bied-Charreton wrote:
> > On Thu, Apr 23, 2026 at 02:24:30PM +0200, Shannon Sterz wrote:
> >> On Tue Apr 21, 2026 at 1:59 PM CEST, Arthur Bied-Charreton wrote:
> 
> -->8 snip 8<--
> 
> >> > +Google
> >> > +''''''
> >> > +
> >> > +Google does not allow bare IP addresses as redirect URIs. To work around this,
> >> > +add an entry to ``/etc/hosts`` **on the machine where your browser is
> >> > +running**, i.e., your local workstation.
> >> > +
> >> > +::
> >> > +
> >> > +    # Replace <IP> with the IP address of your Proxmox Backup Server node
> >> > +    <IP> local.oauth2-redirect.com
> >> > +
> >>
> >> not sure if that makes sense here. what if the device a user is using
> >> doesn't allow changing the hosts file (e.g. insufficient permissions or
> >> they are using a locked down phone etc.)?
> >>
> >> if we do add this section, consider using a reserved second level domain
> >> instead [1]. using a domain that could be be registered and misused
> >> seems dangerous to me.
> >>
> >> [1]: https://datatracker.ietf.org/doc/html/rfc2606#section-3
> >>
> > Thanks for the feedback! I am actually unsure if this hack even belongs
> > in our docs now that I think about it again. Maybe it would suffice to
> > just add a warning stating that Google does not allow bare IP addresses
> > and let users figure out how they want to work around that, or even
> > remove it altogether - what do you think? It is not really related to
> > PBS itself after all.
> >
> 
> yes adding a warning that bare ips aren't accepted and dropping the
> work-around section seems reasonable to me. we tend to target an
> audience that can probably figure out a work around if needed. so it
> shouldn't be to hard to come up with a way to make address resolution
> work on their end.
> 
> if you want to keep a hint at the host file around you could do
> something like this imo:
> 
> .. NOTE:: Google does not allow IP addresses as redirect URIs. If you
>    need to work around this, specify a dummy domain as the redirect URI
>    and make sure that your local machine resolves it to the proper IP
>    address (by, for example, adding a line to ``/etc/hosts``).
> 
> and leave it at that, most of our users should hopefully be able to
> figure out how to make this work for them.
> 
> -->8 snip 8<--
Sounds good, will do that - thank you for the review!