From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from firstgate.proxmox.com (firstgate.proxmox.com [212.224.123.68]) by lore.proxmox.com (Postfix) with ESMTPS id 8B03A1FF142 for ; Tue, 21 Apr 2026 14:04:13 +0200 (CEST) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id 09CEA1FF85; Tue, 21 Apr 2026 14:01:02 +0200 (CEST) From: Arthur Bied-Charreton To: pbs-devel@lists.proxmox.com, pve-devel@lists.proxmox.com Subject: [PATCH proxmox-backup v4 23/24] notifications: Add OAuth2 section to SMTP target docs Date: Tue, 21 Apr 2026 13:59:56 +0200 Message-ID: <20260421115957.402589-24-a.bied-charreton@proxmox.com> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260421115957.402589-1-a.bied-charreton@proxmox.com> References: <20260421115957.402589-1-a.bied-charreton@proxmox.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SPAM-LEVEL: Spam detection results: 0 AWL -0.115 Adjusted score from AWL reputation of From: address BAYES_00 -1.9 Bayes spam probability is 0 to 1% DMARC_MISSING 0.1 Missing DMARC policy KAM_DMARC_STATUS 0.01 Test Rule for DKIM or SPF Failure with Strict Alignment KAM_LAZY_DOMAIN_SECURITY 1 Sending domain does not have any anti-forgery methods RDNS_NONE 0.793 Delivered to internal network by a host with no rDNS SPF_HELO_NONE 0.001 SPF: HELO does not publish an SPF Record SPF_NONE 0.001 SPF: sender does not publish an SPF Record WEIRD_PORT 0.001 Uses non-standard port number for HTTP WEIRD_QUOTING 0.001 Weird repeated double-quotation marks Message-ID-Hash: ALSMDLXIQZDZU46TAHB7YK7L3AZECJJC X-Message-ID-Hash: ALSMDLXIQZDZU46TAHB7YK7L3AZECJJC X-MailFrom: abied-charreton@jett.proxmox.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; loop; banned-address; emergency; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header X-Mailman-Version: 3.3.10 Precedence: list List-Id: Proxmox VE development discussion List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: Document the new SMTP notification target option, especially that: 1. User intervention is required for initial setup, and 2. Microsoft OAuth2 apps *must not* be configured as SPAs by the user, since it would prevent PBS from automatically extending the refresh token's lifetime. Signed-off-by: Arthur Bied-Charreton --- docs/notifications.rst | 102 +++++++++++++++++++++++++++++++++++++++++ www/OnlineHelpInfo.js | 12 +++++ 2 files changed, 114 insertions(+) diff --git a/docs/notifications.rst b/docs/notifications.rst index 992ef152..935650bb 100644 --- a/docs/notifications.rst +++ b/docs/notifications.rst @@ -69,6 +69,108 @@ address will be used. See :ref:`notifications.cfg` for all configuration options. +.. _notification_targets_smtp_oauth2: + +OAuth2 Authentication +""""""""""""""""""""" + +Proxmox Backup Server supports OAuth2 authentication for SMTP targets via the +XOAUTH2 mechanism. This is currently available for Google and Microsoft mail +providers. + +Creating an OAuth2 Application +'''''''''''''''''''''''''''''' + +Before configuring OAuth2 in Proxmox Backup Server, you must register an OAuth2 +application with your mail provider: + +* `Google `_ +* `Microsoft Entra ID `_ + +Choose **Web application** as application type. + +During registration, add a redirect URI pointing to the Proxmox Backup Server +web interface URL from which you will perform the authorization flow, for +example: + +* ``https://pbs1.yourdomain.com:8007`` +* ``https://localhost:8007`` + +You can add multiple redirect URIs to allow the authorization flow to work from +any node. + +.. NOTE:: Google does not allow bare IP addresses as redirect URIs. See + :ref:`Google-specific setup ` below + for a workaround. + +Configuring OAuth2 in Proxmox Backup Server +''''''''''''''''''''''''''''''''''''''''''' + +In the web UI, open the notification target's edit panel and select +``OAuth2 (Google)`` or ``OAuth2 (Microsoft)`` as the authentication method. +Fill in the client ID and secret. For Microsoft, also fill in the tenant ID. + +Click **Authorize**. This opens a new window where you can sign in with your +mail provider and grant the requested permissions. On success, a refresh token +is obtained and stored. + +Token refresh happens automatically, at least once every 24 hours. If the token +expires due to extended downtime or is revoked, you will need to re-authorize: +open the notification target's edit panel, fill in your client secret, and +click **Authorize** again. + +.. NOTE:: OAuth2 cannot be configured through direct configuration file + editing. Use the web interface, or alternatively ``proxmox-backup-manager``, + to configure OAuth2 targets. Note that when using ``proxmox-backup-manager``, + you are responsible for providing the initial refresh token. + +:: + + proxmox-backup-manager notification endpoint smtp create oauth2-smtp \ + --server smtp.example.com \ + --from-address from@gmail.com \ + --mailto-user root@pam \ + --auth-method google-oauth2 \ + --oauth2-client-id \ + --oauth2-client-secret \ + --oauth2-refresh-token + +For Microsoft, use ``--auth-method microsoft-oauth2`` and add +``--oauth2-tenant-id ``. + +.. _notification_targets_smtp_oauth2_google: + +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 with the IP address of your Proxmox Backup Server node + local.oauth2-redirect.com + +You can now register ``https://local.oauth2-redirect.com:8007`` as a redirect +URI in your Google OAuth2 application, and use that same URL in the browser +when accessing the Proxmox Backup Server web interface to perform the +authorization flow. + +.. _notification_targets_smtp_oauth2_microsoft: + +Microsoft +''''''''' + +.. WARNING:: For Microsoft, the application must **not** be registered as a + Single-Page Application (SPA). Proxmox Backup Server requires long-lived + refresh tokens, and Microsoft does not allow extending the lifetime of + refresh tokens granted for SPAs. + +Register your OAuth2 application as a standard **Web** application in the +Entra admin center. In addition to the client ID and secret, you will also +need the **tenant ID** from your application registration. + .. _notification_targets_gotify: Gotify diff --git a/www/OnlineHelpInfo.js b/www/OnlineHelpInfo.js index 89650cfb..95daed6f 100644 --- a/www/OnlineHelpInfo.js +++ b/www/OnlineHelpInfo.js @@ -251,6 +251,18 @@ const proxmoxOnlineHelpInfo = { "link": "/docs/notifications.html#notification-targets-smtp", "title": "SMTP" }, + "notification-targets-smtp-oauth2": { + "link": "/docs/notifications.html#notification-targets-smtp-oauth2", + "title": "OAuth2 Authentication" + }, + "notification-targets-smtp-oauth2-google": { + "link": "/docs/notifications.html#notification-targets-smtp-oauth2-google", + "title": "Google" + }, + "notification-targets-smtp-oauth2-microsoft": { + "link": "/docs/notifications.html#notification-targets-smtp-oauth2-microsoft", + "title": "Microsoft" + }, "notification-targets-gotify": { "link": "/docs/notifications.html#notification-targets-gotify", "title": "Gotify" -- 2.47.3