dbus: rauc: add support for enabling the auto install feature

Automatic installation and boot of updates can be useful when managing a
fleet of devices. This is however a feature that requires strict user
consent, hence why it is off by default.

Add backend-support for enabling this feature. Frontent support in the
web interface will be added later.

We always enable auto-reboot together with auto-install,
since the migration scripts only run once at the end of the installation.
A system that is updated, but not rebooted, would thus accumulate changes
that are not migrated to the other slot.

Signed-off-by: Leonard Göhrs <l.goehrs@pengutronix.de>

Author: hnez

openapi.yaml

@@ -775,6 +775,21 @@ paths:
         '400':
           description: The value could not be parsed as boolean
 
+  /v1/tac/update/enable_auto_install:
+    put:
+      summary: Enable automatic installation of operating system updates
+      tags: [Updating]
+      requestBody:
+        content:
+          application/json:
+            schema:
+              type: boolean
+      responses:
+        '204':
+          description: Automatic installation of updates was enabled/disabled
+        '400':
+          description: The value could not be parsed as boolean
+
   /v1/tac/update/operation:
     get:
       summary: Get the currently running system update operation

src/dbus/rauc.rs

@@ -140,6 +140,7 @@ pub struct Rauc {
     pub reload: Arc<Topic<bool>>,
     pub should_reboot: Arc<Topic<bool>>,
     pub enable_polling: Arc<Topic<bool>>,
+    pub enable_auto_install: Arc<Topic<bool>>,
 }
 
 #[cfg(not(feature = "demo_mode"))]
@@ -205,15 +206,18 @@ async fn channel_list_update_task(
     conn: Arc<Connection>,
     reload: Arc<Topic<bool>>,
     enable_polling: Arc<Topic<bool>>,
+    enable_auto_install: Arc<Topic<bool>>,
     channels: Arc<Topic<Channels>>,
     rauc_service: Service,
 ) -> Result<()> {
     let poller = PollerProxy::new(&conn).await.unwrap();
 
     let (reload_stream, _) = reload.subscribe_unbounded();
     let (mut enable_polling_stream, _) = enable_polling.subscribe_unbounded();
+    let (mut enable_auto_install_stream, _) = enable_auto_install.subscribe_unbounded();
 
     let mut enable_polling = enable_polling_stream.next().await.unwrap_or(false);
+    let mut enable_auto_install = enable_auto_install_stream.next().await.unwrap_or(false);
 
     'reload_loop: loop {
         futures::select! {
@@ -225,6 +229,9 @@ async fn channel_list_update_task(
             enable_polling_new = enable_polling_stream.recv().fuse() => {
                 enable_polling = enable_polling_new?;
             }
+            enable_auto_install_new = enable_auto_install_stream.recv().fuse() => {
+                enable_auto_install = enable_auto_install_new?;
+            }
         };
 
         // Read the list of available update channels
@@ -236,7 +243,8 @@ async fn channel_list_update_task(
             }
         };
 
-        let should_reload = update_system_conf(new_channels.primary(), enable_polling)?;
+        let should_reload =
+            update_system_conf(new_channels.primary(), enable_polling, enable_auto_install)?;
 
         channels.set(new_channels);
 
@@ -304,6 +312,14 @@ impl Rauc {
                 Some(false),
                 1,
             ),
+            enable_auto_install: bb.topic(
+                "/v1/tac/update/enable_auto_install",
+                true,
+                true,
+                true,
+                Some(false),
+                1,
+            ),
         }
     }
 
@@ -327,6 +343,7 @@ impl Rauc {
                 Arc::new(Connection),
                 inst.reload.clone(),
                 inst.enable_polling.clone(),
+                inst.enable_auto_install.clone(),
                 inst.channels.clone(),
                 rauc_service,
             ),
@@ -595,6 +612,7 @@ impl Rauc {
                 conn.clone(),
                 inst.reload.clone(),
                 inst.enable_polling.clone(),
+                inst.enable_auto_install.clone(),
                 inst.channels.clone(),
                 rauc_service,
             ),

src/dbus/rauc/system_conf.rs

@@ -26,6 +26,7 @@ const MAGIC_LINE: &str = "\n# <tacd-poll-section>\n";
 fn poll_section(
     primary_channel: Option<&Channel>,
     polling: bool,
+    auto_install: bool,
 ) -> Result<Option<String>, std::fmt::Error> {
     // If no primary channel is configured or if polling is not enabled,
     // then we do not need a `[poll]` section at all.
@@ -46,15 +47,25 @@ fn poll_section(
 
     writeln!(&mut section, "candidate-criteria=different-version")?;
 
+    if auto_install {
+        writeln!(&mut section, "install-criteria=different-version")?;
+        writeln!(
+            &mut section,
+            "reboot-criteria=updated-slots;updated-artifacts"
+        )?;
+        writeln!(&mut section, "reboot-cmd=systemctl reboot")?;
+    }
+
     Ok(Some(section))
 }
 
 pub fn update_system_conf(
     primary_channel: Option<&Channel>,
     enable_polling: bool,
+    enable_auto_install: bool,
 ) -> std::io::Result<bool> {
     let dynamic_conf = {
-        match poll_section(primary_channel, enable_polling) {
+        match poll_section(primary_channel, enable_polling, enable_auto_install) {
             Ok(Some(ps)) => {
                 // We use the config in /etc as a template ...
                 let static_conf = read_to_string(STATIC_CONF_PATH)?;