Re: [PATCH pve-docs 1/1] notifications: Add section about OAuth2 to SMTP targets docs

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

On Wed, Feb 11, 2026 at 11:06:24AM +0100, Lukas Wagner wrote:
> Hi!
> 
> Nice work overall, some hints for some refinements for the next version
> inline.
> 
> On Wed Feb 4, 2026 at 5:13 PM CET, Arthur Bied-Charreton wrote:
> > Document the new config entries, and add notes/warnings to communicate
> > that:
> >
> > 1. User intervention is required for initial OAuth2 target setup, and
> >
> > 2. Microsoft OAuth2 apps *must not* be configured as SPAs by the
> > user, since it would prevent PVE from automatically extending the
> > refresh token's lifetime
> >
> > Signed-off-by: Arthur Bied-Charreton <a.bied-charreton@proxmox.com>
> > ---
> >  notifications.adoc | 44 ++++++++++++++++++++++++++++++++++++++++----
> >  1 file changed, 40 insertions(+), 4 deletions(-)
> >
> > diff --git a/notifications.adoc b/notifications.adoc
> > index 801b327..679b19b 100644
> > --- a/notifications.adoc
> > +++ b/notifications.adoc
> > @@ -108,16 +108,23 @@ The configuration for SMTP target plugins has the following options:
> >  * `from-address`: Sets the From-address of the email. SMTP relays might require
> >    that this address is owned by the user in order to avoid spoofing.  The `From`
> >    header in the email will be set to `$author <$from-address>`.
> > +* `auth-method`: Sets the authentication method (`plain`, `google-oauth2` or
> > +  `microsoft-oauth2`).
> >  * `username`: Username to use during authentication. If no username is set,
> >    no authentication will be performed. The PLAIN and LOGIN authentication
> >    methods are supported.
> >  * `password`: Password to use when authenticating.
> > +* `oauth2-client-id`: Client ID for the OAuth2 application, if applicable.
> > +* `oauth2-client-secret`: Client secret for the OAuth2 application, if
> > +  applicable.
> > +* `oauth2-tenant-id`: Tenant ID for the OAuth2 application, if applicable.
> > +  Only required for Microsoft OAuth2.
> >  * `mode`: Sets the encryption mode (`insecure`, `starttls` or `tls`). Defaults
> >    to `tls`.
> >  * `server`: Address/IP of the SMTP relay.
> 
> 
> 
> > -* `port`: The port to connect to. If not set, the used port .
> > -   Defaults to 25 (`insecure`), 465 (`tls`) or 587 (`starttls`), depending on
> > -   the value of `mode`.
> > +* `port`: The port to connect to. If not set, the used port defaults to 25
> > +  (`insecure`), 465 (`tls`) or 587 (`starttls`), depending on the value of
> > +  `mode`.
> >  * `comment`: Comment for this target
> 
> Thanks for fixing this up, but since this is completely unrelated to
> your OAuth changes, this should rather be a separate commit (as the
> first-patch of the pve-docs part of the series - since then it can be
> applied independently while this series as a whole is still in progress)
> 
> >  
> >  Example configuration (`/etc/pve/notifications.cfg`):
> > @@ -133,13 +140,42 @@ smtp: example
> >  ----
> >  
> >  The matching entry in `/etc/pve/priv/notifications.cfg`, containing the
> > -secret token:
> > +password:
> >  
> >  ----
> >  smtp: example
> >          password somepassword
> >  ----
> 
> this here as well
> 
Thanks, sent a separate patch:
https://lore.proxmox.com/pve-devel/20260211131323.232299-1-a.bied-charreton@proxmox.com/T/#u
> >  
> > +[[notification_targets_smtp_oauth2]]
> > +===== OAuth2 Authentication
> > +
> > +SMTP targets also support OAuth2 authentication via the XOAUTH2 mechanism for
> > +Google and Microsoft mail providers.
> > +
> > +Setting up OAuth2 authentication requires creating an OAuth2 application with
> > +the chosen provider. The application must be configured with a redirect URI
> > +pointing to the {pve} web interface, i.e. the URL from which the initial
> > +authentication request is performed in the UI.
> 
> I guess you could also mention that one could add all cluster nodes as
> permitted origins and redirect URIs. It would also be good to maybe add
> some concrete examples for sensible origins and redirect URIs,
> mentioning common restrictions (e.g. Google not allowing IPs)
> 
> > +
> > +CAUTION: For Microsoft, the application must *not* be registered as Single-Page
> > +Application (SPA), as the lifetime of refresh tokens granted for SPAs cannot
> > +be extended automatically by {pve}.
> > +
> > +To set up OAuth2 authentication via the web interface, select `OAuth2 (Google)`
> > +or `OAuth2 (Microsoft)` as the authentication method, fill in the client ID and
> > +secret (and the tenant ID for Microsoft), then click the *Authenticate* button.
> > +This opens a new window where you can sign in with the selected provider and
> > +grant the required permissions. Upon successful authentication, a refresh
> > +token is obtained and stored automatically.
> > +
> > +Token refresh happens automatically, manual intervention is only needed if a
> > +token is revoked.
> 
> Maybe elaborate what 'manual intervention' means in this case (I assume
> re-authorize?) . Also could not hurt to mention the pvesh command to
> trigger a manual token refresh.
> 
> > +
> > +NOTE: OAuth2 is currently not configurable through direct configuration file
> > +editing because the refresh token is managed as dynamic state by {pve}. All
> > +OAuth2 targets must be configured via the web interface.
> 
> Maybe mention that one could also add the endpoint by using the
> appropriate API endoint, supplying a token that they requested by other
> means.
> 
> > +
> >  [[notification_targets_gotify]]
> >  Gotify
> >  ~~~~~~
> 
Thanks, will update the docs accordingly!