lib: add support for soft-reboots

crates/lib/src/cli.rs

@@ -80,6 +80,13 @@ pub(crate) struct UpgradeOpts {
     #[clap(long, conflicts_with = "check")]
     pub(crate) apply: bool,
 
+    /// Configure soft reboot behavior.
+    ///
+    /// 'required' will fail if soft reboot is not available.
+    /// 'auto' will use soft reboot if available, otherwise fall back to regular reboot.
+    #[clap(long = "soft-reboot", conflicts_with = "check")]
+    pub(crate) soft_reboot: Option<SoftRebootMode>,
+
     #[clap(flatten)]
     pub(crate) progress: ProgressOptions,
 }
@@ -99,6 +106,13 @@ pub(crate) struct SwitchOpts {
     #[clap(long)]
     pub(crate) apply: bool,
 
+    /// Configure soft reboot behavior.
+    ///
+    /// 'required' will fail if soft reboot is not available.
+    /// 'auto' will use soft reboot if available, otherwise fall back to regular reboot.
+    #[clap(long = "soft-reboot")]
+    pub(crate) soft_reboot: Option<SoftRebootMode>,
+
     /// The transport; e.g. oci, oci-archive, containers-storage.  Defaults to `registry`.
     #[clap(long, default_value = "registry")]
     pub(crate) transport: String,
@@ -142,6 +156,13 @@ pub(crate) struct RollbackOpts {
     /// a userspace-only restart.
     #[clap(long)]
     pub(crate) apply: bool,
+
+    /// Configure soft reboot behavior.
+    ///
+    /// 'required' will fail if soft reboot is not available.
+    /// 'auto' will use soft reboot if available, otherwise fall back to regular reboot.
+    #[clap(long = "soft-reboot")]
+    pub(crate) soft_reboot: Option<SoftRebootMode>,
 }
 
 /// Perform an edit operation
@@ -167,6 +188,15 @@ pub(crate) enum OutputFormat {
     Json,
 }
 
+#[derive(Debug, Clone, Copy, ValueEnum, PartialEq, Eq)]
+#[clap(rename_all = "lowercase")]
+pub(crate) enum SoftRebootMode {
+    /// Require a soft reboot; fail if not possible
+    Required,
+    /// Automatically use soft reboot if possible, otherwise use regular reboot
+    Auto,
+}
+
 /// Perform an status operation
 #[derive(Debug, Parser, PartialEq, Eq)]
 pub(crate) struct StatusOpts {
@@ -562,7 +592,7 @@ pub(crate) enum Opt {
         Note on Rollbacks and the `/etc` Directory:
 
         When you perform a rollback (e.g., with `bootc rollback`), any
-        changes made to files in the `/etc` directory won’t carry over
+        changes made to files in the `/etc` directory won't carry over
         to the rolled-back deployment.  The `/etc` files will revert
         to their state from that previous deployment instead.
 
@@ -741,6 +771,104 @@ pub(crate) fn require_root(is_container: bool) -> Result<()> {
     Ok(())
 }
 
+/// Check if a deployment has soft reboot capability
+fn has_soft_reboot_capability(deployment: Option<&crate::spec::BootEntry>) -> bool {
+    deployment.map(|d| d.soft_reboot_capable).unwrap_or(false)
+}
+
+/// Prepare a soft reboot for the given deployment
+#[context("Preparing soft reboot")]
+fn prepare_soft_reboot(
+    sysroot: &crate::store::Storage,
+    deployment: &ostree::Deployment,
+) -> Result<()> {
+    let cancellable = ostree::gio::Cancellable::NONE;
+    sysroot
+        .sysroot
+        .deployment_set_soft_reboot(deployment, false, cancellable)
+        .context("Failed to prepare soft-reboot")?;
+    Ok(())
+}
+
+/// Handle soft reboot based on the configured mode
+#[context("Handling soft reboot")]
+fn handle_soft_reboot<F>(
+    soft_reboot_mode: Option<SoftRebootMode>,
+    entry: Option<&crate::spec::BootEntry>,
+    deployment_type: &str,
+    execute_soft_reboot: F,
+) -> Result<()>
+where
+    F: FnOnce() -> Result<()>,
+{
+    let Some(mode) = soft_reboot_mode else {
+        return Ok(());
+    };
+
+    let can_soft_reboot = has_soft_reboot_capability(entry);
+    match mode {
+        SoftRebootMode::Required => {
+            if can_soft_reboot {
+                execute_soft_reboot()?;
+            } else {
+                anyhow::bail!(
+                    "Soft reboot was required but {} deployment is not soft-reboot capable",
+                    deployment_type
+                );
+            }
+        }
+        SoftRebootMode::Auto => {
+            if can_soft_reboot {
+                execute_soft_reboot()?;
+            }
+        }
+    }
+    Ok(())
+}
+
+/// Handle soft reboot for staged deployments (used by upgrade and switch)
+#[context("Handling staged soft reboot")]
+fn handle_staged_soft_reboot(
+    sysroot: &crate::store::Storage,
+    soft_reboot_mode: Option<SoftRebootMode>,
+    host: &crate::spec::Host,
+) -> Result<()> {
+    handle_soft_reboot(
+        soft_reboot_mode,
+        host.status.staged.as_ref(),
+        "staged",
+        || soft_reboot_staged(sysroot),
+    )
+}
+
+/// Perform a soft reboot for a staged deployment
+#[context("Soft reboot staged deployment")]
+fn soft_reboot_staged(sysroot: &crate::store::Storage) -> Result<()> {
+    println!("Staged deployment is soft-reboot capable, preparing for soft-reboot...");
+
+    let deployments_list = sysroot.deployments();
+    let staged_deployment = deployments_list
+        .iter()
+        .find(|d| d.is_staged())
+        .ok_or_else(|| anyhow::anyhow!("Failed to find staged deployment"))?;
+
+    prepare_soft_reboot(sysroot, staged_deployment)?;
+    Ok(())
+}
+
+/// Perform a soft reboot for a rollback deployment
+#[context("Soft reboot rollback deployment")]
+fn soft_reboot_rollback(sysroot: &crate::store::Storage) -> Result<()> {
+    println!("Rollback deployment is soft-reboot capable, preparing for soft-reboot...");
+
+    let deployments_list = sysroot.deployments();
+    let target_deployment = deployments_list
+        .first()
+        .ok_or_else(|| anyhow::anyhow!("No rollback deployment found!"))?;
+
+    prepare_soft_reboot(sysroot, target_deployment)
+}
+
 /// A few process changes that need to be made for writing.
 /// IMPORTANT: This may end up re-executing the current process,
 /// so anything that happens before this should be idempotent.
@@ -813,6 +941,7 @@ async fn upgrade(opts: UpgradeOpts) -> Result<()> {
     let booted_image = host
         .status
         .booted
+        .as_ref()
         .map(|b| b.query_image(repo))
         .transpose()?
         .flatten();
@@ -859,7 +988,7 @@ async fn upgrade(opts: UpgradeOpts) -> Result<()> {
             .unwrap_or_default();
         if staged_unchanged {
             println!("Staged update present, not changed.");
-
+            handle_staged_soft_reboot(sysroot, opts.soft_reboot, &host)?;
             if opts.apply {
                 crate::reboot::reboot()?;
             }
@@ -881,6 +1010,13 @@ async fn upgrade(opts: UpgradeOpts) -> Result<()> {
     if changed {
         sysroot.update_mtime()?;
 
+        if opts.soft_reboot.is_some() {
+            // At this point we have new staged deployment and the host definition has changed.
+            // We need the updated host status before we check if we can prepare the soft-reboot.
+            let updated_host = crate::status::get_status(sysroot, Some(&booted_deployment))?.1;
+            handle_staged_soft_reboot(sysroot, opts.soft_reboot, &updated_host)?;
+        }
+
         if opts.apply {
             crate::reboot::reboot()?;
         }
@@ -956,6 +1092,13 @@ async fn switch(opts: SwitchOpts) -> Result<()> {
 
     sysroot.update_mtime()?;
 
+    if opts.soft_reboot.is_some() {
+        // At this point we have staged the deployment and the host definition has changed.
+        // We need the updated host status before we check if we can prepare the soft-reboot.
+        let updated_host = crate::status::get_status(sysroot, Some(&booted_deployment))?.1;
+        handle_staged_soft_reboot(sysroot, opts.soft_reboot, &updated_host)?;
+    }
+
     if opts.apply {
         crate::reboot::reboot()?;
     }
@@ -969,6 +1112,18 @@ async fn rollback(opts: RollbackOpts) -> Result<()> {
     let sysroot = &get_storage().await?;
     crate::deploy::rollback(sysroot).await?;
 
+    if opts.soft_reboot.is_some() {
+        // Get status of rollback deployment to check soft-reboot capability
+        let host = crate::status::get_status_require_booted(sysroot)?.2;
+
+        handle_soft_reboot(
+            opts.soft_reboot,
+            host.status.rollback.as_ref(),
+            "rollback",
+            || soft_reboot_rollback(sysroot),
+        )?;
+    }
+
     if opts.apply {
         crate::reboot::reboot()?;
     }

crates/lib/src/spec.rs

@@ -176,6 +176,9 @@ pub struct BootEntry {
     pub incompatible: bool,
     /// Whether this entry will be subject to garbage collection
     pub pinned: bool,
+    /// This is true if (relative to the booted system) this is a possible target for a soft reboot
+    #[serde(default)]
+    pub soft_reboot_capable: bool,
     /// The container storage backend
     #[serde(default)]
     pub store: Option<Store>,
@@ -517,6 +520,7 @@ mod tests {
                 image: None,
                 cached_update: None,
                 incompatible: false,
+                soft_reboot_capable: false,
                 pinned: false,
                 store: None,
                 ostree: None,

crates/lib/src/status.rs

@@ -90,6 +90,11 @@ impl From<ImageReference> for OstreeImageReference {
     }
 }
 
+/// Check if a deployment has soft reboot capability
+fn has_soft_reboot_capability(sysroot: &Storage, deployment: &ostree::Deployment) -> bool {
+    ostree_ext::systemd_has_soft_reboot() && sysroot.deployment_can_soft_reboot(deployment)
+}
+
 /// Parse an ostree origin file (a keyfile) and extract the targeted
 /// container image reference.
 fn get_image_origin(origin: &glib::KeyFile) -> Result<Option<OstreeImageReference>> {
@@ -187,11 +192,13 @@ fn boot_entry_from_deployment(
         (CachedImageStatus::default(), false)
     };
 
+    let soft_reboot_capable = has_soft_reboot_capability(sysroot, deployment);
     let store = Some(crate::spec::Store::OstreeContainer);
     let r = BootEntry {
         image,
         cached_update,
         incompatible,
+        soft_reboot_capable,
         store,
         pinned: deployment.is_pinned(),
         ostree: Some(crate::spec::BootEntryOstree {
@@ -425,6 +432,27 @@ fn render_verbose_ostree_info(
     Ok(())
 }
 
+/// Helper function to render if soft-reboot capable
+fn write_soft_reboot(
+    mut out: impl Write,
+    entry: &crate::spec::BootEntry,
+    prefix_len: usize,
+) -> Result<()> {
+    // Show soft-reboot capability
+    write_row_name(&mut out, "Soft-reboot", prefix_len)?;
+    writeln!(
+        out,
+        "{}",
+        if entry.soft_reboot_capable {
+            "yes"
+        } else {
+            "no"
+        }
+    )?;
+
+    Ok(())
+}
+
 /// Write the data for a container image based status.
 fn human_render_slot(
     mut out: impl Write,
@@ -507,6 +535,9 @@ fn human_render_slot(
                 }
             }
         }
+
+        // Show soft-reboot capability
+        write_soft_reboot(&mut out, entry, prefix_len)?;
     }
 
     tracing::debug!("pinned={}", entry.pinned);
@@ -544,6 +575,9 @@ fn human_render_slot_ostree(
         if let Some(ostree) = &entry.ostree {
             render_verbose_ostree_info(&mut out, ostree, slot, prefix_len)?;
         }
+
+        // Show soft-reboot capability
+        write_soft_reboot(&mut out, entry, prefix_len)?;
     }
 
     tracing::debug!("pinned={}", entry.pinned);
@@ -765,5 +799,6 @@ mod tests {
         assert!(w.contains("Deploy serial:"));
         assert!(w.contains("Staged:"));
         assert!(w.contains("Commit:"));
+        assert!(w.contains("Soft-reboot:"));
     }
 }

crates/ostree-ext/Cargo.toml

@@ -50,7 +50,7 @@ io-lifetimes = "3"
 libsystemd = "0.7.0"
 ocidir = "0.4.0"
 # We re-export this library too.
-ostree = { features = ["v2025_2"], version = "0.20" }
+ostree = { features = ["v2025_3"], version = "0.20.3" }
 pin-project = "1.0"
 tar = "0.4.43"
 tokio-stream = { features = ["sync"], version = "0.1.8" }

crates/ostree-ext/src/lib.rs

@@ -78,3 +78,12 @@ pub mod prelude {
 pub mod fixture;
 #[cfg(feature = "internal-testing-api")]
 pub mod integrationtest;
+
+/// Check if the system has the soft reboot target, which signals
+/// systemd support for soft reboots.
+pub fn systemd_has_soft_reboot() -> bool {
+    const UNIT: &str = "/usr/lib/systemd/system/soft-reboot.target";
+    use std::sync::OnceLock;
+    static EXISTS: OnceLock<bool> = OnceLock::new();
+    *EXISTS.get_or_init(|| std::path::Path::new(UNIT).exists())
+}

tmt/plans/integration.fmf

@@ -62,3 +62,11 @@ execute:
     test:
         - /tmt/tests/bootc-install-provision
         - /tmt/tests/test-24-local-upgrade-reboot
+
+/test-25-soft-reboot:
+  summary: Soft reboot support
+  discover:
+    how: fmf
+    test:
+        - /tmt/tests/bootc-install-provision
+        - /tmt/tests/test-25-soft-reboot