api: apt: implement support to send notification email on new updates

again, base idea copied off PVE, but, we safe the information about
which pending version we send a mail out already in a separate
object, to keep the api return type APTUpdateInfo clean.

This also makes a few things a bit easier, as we can update the
package status without saving/restoring the notify information.

Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>

src/api2/node/apt.rs

@@ -85,6 +85,13 @@ fn do_apt_update(worker: &WorkerTask, quiet: bool) -> Result<(), Error> {
             node: {
                 schema: NODE_SCHEMA,
             },
+            notify: {
+                type: bool,
+                description: r#"Send notification mail about new package updates availanle to the
+                    email address configured for 'root@pam')."#,
+                optional: true,
+                default: false,
+            },
             quiet: {
                 description: "Only produces output suitable for logging, omitting progress indicators.",
                 type: bool,
@@ -102,16 +109,46 @@ fn do_apt_update(worker: &WorkerTask, quiet: bool) -> Result<(), Error> {
 )]
 /// Update the APT database
 pub fn apt_update_database(
+    notify: Option<bool>,
     quiet: Option<bool>,
     rpcenv: &mut dyn RpcEnvironment,
 ) -> Result<String, Error> {
 
     let auth_id: Authid = rpcenv.get_auth_id().unwrap().parse()?;
     let to_stdout = if rpcenv.env_type() == RpcEnvironmentType::CLI { true } else { false };
+    // FIXME: change to non-option in signature and drop below once we have proxmox-api-macro 0.2.3
     let quiet = quiet.unwrap_or(API_METHOD_APT_UPDATE_DATABASE_PARAM_DEFAULT_QUIET);
+    let notify = notify.unwrap_or(API_METHOD_APT_UPDATE_DATABASE_PARAM_DEFAULT_NOTIFY);
 
     let upid_str = WorkerTask::new_thread("aptupdate", None, auth_id, to_stdout, move |worker| {
         do_apt_update(&worker, quiet)?;
+
+        let mut cache = apt::update_cache()?;
+
+        if notify {
+            let mut notified = match cache.notified {
+                Some(notified) => notified,
+                None => std::collections::HashMap::new(),
+            };
+            let mut to_notify: Vec<&APTUpdateInfo> = Vec::new();
+
+            for pkg in &cache.package_status {
+                match notified.insert(pkg.package.to_owned(), pkg.version.to_owned()) {
+                    Some(notified_version) => {
+                        if notified_version != pkg.version {
+                            to_notify.push(pkg);
+                        }
+                    },
+                    None => to_notify.push(pkg),
+                }
+            }
+            if !to_notify.is_empty() {
+                crate::server::send_updates_available(&to_notify)?;
+            }
+            cache.notified = Some(notified);
+            apt::write_pkg_cache(&cache)?;
+        }
+
         Ok(())
     })?;
 

src/server/email_notifications.rs

@@ -9,8 +9,9 @@ use crate::{
     config::verify::VerificationJobConfig,
     config::sync::SyncJobConfig,
     api2::types::{
-        Userid,
+        APTUpdateInfo,
         GarbageCollectionStatus,
+        Userid,
     },
     tools::format::HumanByte,
 };
@@ -91,6 +92,16 @@ Synchronization failed: {{error}}
 
 "###;
 
+const PACKAGE_UPDATES_TEMPLATE: &str = r###"
+Proxmox Backup Server has the following updates available:
+{{#each updates }}
+  {{Package}}: {{OldVersion}} -> {{Version~}}
+{{/each }}
+
+To upgrade visit the webinderface: <https://{{fqdn}}:{{port}}/#pbsServerAdministration:updates>
+"###;
+
+
 lazy_static::lazy_static!{
 
     static ref HANDLEBARS: Handlebars<'static> = {
@@ -110,6 +121,8 @@ lazy_static::lazy_static!{
         hb.register_template_string("sync_ok_template", SYNC_OK_TEMPLATE).unwrap();
         hb.register_template_string("sync_err_template", SYNC_ERR_TEMPLATE).unwrap();
 
+        hb.register_template_string("package_update_template", PACKAGE_UPDATES_TEMPLATE).unwrap();
+
         hb
     };
 }
@@ -261,6 +274,25 @@ pub fn send_sync_status(
     Ok(())
 }
 
+pub fn send_updates_available(
+    updates: &Vec<&APTUpdateInfo>,
+) -> Result<(), Error> {
+    // update mails always go to the root@pam configured email..
+    if let Some(email) = lookup_user_email(Userid::root_userid()) {
+        let nodename = proxmox::tools::nodename();
+        let subject = format!("New software packages available ({})", nodename);
+
+        let text = HANDLEBARS.render("package_update_template", &json!({
+            "fqdn": nix::sys::utsname::uname().nodename(), // FIXME: add get_fqdn helper like PVE?
+            "port": 8007, // user will surely request that they can change this
+            "updates": updates,
+        }))?;
+
+        send_job_status_mail(&email, &subject, &text)?;
+    }
+    Ok(())
+}
+
 /// Lookup users email address
 ///
 /// For "backup@pam", this returns the address from "root@pam".

src/tools/apt.rs

@@ -1,4 +1,5 @@
 use std::collections::HashSet;
+use std::collections::HashMap;
 
 use anyhow::{Error, bail, format_err};
 use apt_pkg_native::Cache;
@@ -11,8 +12,11 @@ use crate::api2::types::APTUpdateInfo;
 const APT_PKG_STATE_FN: &str = "/var/lib/proxmox-backup/pkg-state.json";
 
 #[derive(Debug, serde::Serialize, serde::Deserialize)]
-/// Some information we cache about the package (update) state
+/// Some information we cache about the package (update) state, like what pending update version
+/// we already notfied an user about
 pub struct PkgState {
+    /// simple map from package name to most recently notified (emailed) version
+    pub notified: Option<HashMap<String, String>>,
     /// A list of pending updates
     pub package_status: Vec<APTUpdateInfo>,
 }
@@ -64,6 +68,7 @@ pub fn update_cache() -> Result<PkgState, Error> {
                 cache
             },
             _ => PkgState {
+                notified: None,
                 package_status: all_upgradeable,
             },
         };