notifications: add type for APT notification template data

This commit adds a separate type for the data passed to this type of
notification template. Also we make sure that we do not expose any
non-primitive types to the template renderer, any data needed in the
template is mapped into the new dedicated template data type.

This ensures that any changes in types defined in other places do not
leak into the template rendering process by accident.
These changes are also preparation for allowing user-overrides for
notification templates.

This commit also tries to unify the style and naming of template
variables.

Signed-off-by: Lukas Wagner <l.wagner@proxmox.com>
Reviewed-by: Maximiliano Sandoval <m.sandoval@proxmox.com>

src/server/notifications/mod.rs

@@ -23,7 +23,10 @@ const SPOOL_DIR: &str = concatcp!(pbs_buildcfg::PROXMOX_BACKUP_STATE_DIR, "/noti
 
 mod template_data;
 
-use template_data::{AcmeErrTemplateData, CommonData, GcErrTemplateData, GcOkTemplateData};
+use template_data::{
+    AcmeErrTemplateData, CommonData, GcErrTemplateData, GcOkTemplateData,
+    PackageUpdatesTemplateData,
+};
 
 /// Initialize the notification system by setting context in proxmox_notify
 pub fn init() -> Result<(), Error> {
@@ -464,23 +467,21 @@ fn get_server_url() -> (String, usize) {
 }
 
 pub fn send_updates_available(updates: &[&APTUpdateInfo]) -> Result<(), Error> {
-    let (fqdn, port) = get_server_url();
     let hostname = proxmox_sys::nodename().to_string();
 
-    let data = json!({
-        "fqdn": fqdn,
-        "hostname": &hostname,
-        "port": port,
-        "updates": updates,
-    });
-
     let metadata = HashMap::from([
         ("hostname".into(), hostname),
         ("type".into(), "package-updates".into()),
     ]);
 
-    let notification =
-        Notification::from_template(Severity::Info, "package-updates", data, metadata);
+    let template_data = PackageUpdatesTemplateData::new(updates);
+
+    let notification = Notification::from_template(
+        Severity::Info,
+        "package-updates",
+        serde_json::to_value(template_data)?,
+        metadata,
+    );
 
     send_notification(notification)?;
     Ok(())

src/server/notifications/template_data.rs

@@ -1,4 +1,4 @@
-use pbs_api_types::GarbageCollectionStatus;
+use pbs_api_types::{APTUpdateInfo, GarbageCollectionStatus};
 use serde::Serialize;
 
 // NOTE: For some of these types, the `XyzOkTemplateData` and `XyzErrTemplateData`
@@ -144,3 +144,42 @@ pub struct AcmeErrTemplateData {
     /// The error that occured when trying to request the certificate.
     pub error: String,
 }
+
+#[derive(Serialize)]
+#[serde(rename_all = "kebab-case")]
+/// A single package which can be upgraded.
+pub struct UpgradablePackage {
+    /// The name of the package.
+    package_name: String,
+    /// The new version which can be installed.
+    available_version: String,
+    /// The currently installed version.
+    installed_version: String,
+}
+
+/// Template data for the package-updates template.
+#[derive(Serialize)]
+#[serde(rename_all = "kebab-case")]
+pub struct PackageUpdatesTemplateData {
+    /// Common properties.
+    #[serde(flatten)]
+    pub common: CommonData,
+    pub available_updates: Vec<UpgradablePackage>,
+}
+
+impl PackageUpdatesTemplateData {
+    /// Create new a new instance.
+    pub fn new(updates: &[&APTUpdateInfo]) -> Self {
+        Self {
+            common: CommonData::new(),
+            available_updates: updates
+                .iter()
+                .map(|info| UpgradablePackage {
+                    package_name: info.package.clone(),
+                    available_version: info.version.clone(),
+                    installed_version: info.old_version.clone(),
+                })
+                .collect(),
+        }
+    }
+}

templates/default/package-updates-body.txt.hbs

@@ -1,8 +1,8 @@
 Proxmox Backup Server has the following updates available:
-{{#each updates }}
-    {{Package}}: {{OldVersion}} -> {{Version~}}
-{{/each }}
+{{#each available-updates}}
+    {{this.package-name}}: {{this.installed-version}} -> {{this.available-version~}}
+{{/each}}
 
 To upgrade visit the web interface:
 
-<https://{{fqdn}}:{{port}}/#pbsServerAdministration:updates>
+<{{base-url}}/#pbsServerAdministration:updates>

templates/default/package-updates-subject.txt.hbs

@@ -1 +1 @@
-New software packages available ({{ hostname }})
+New software packages available ({{hostname}})