Persist maintenance mode and fix an issue with it

src/loader/zone.rs

@@ -112,8 +112,9 @@ impl LoaderZoneHandle<'_> {
     /// Start a pending enqueued refresh.
     ///
     /// This should be called when the zone data storage is in the passive
-    /// state. If a load has been enqueued, it will be initiated (making the
-    /// data storage busy), and `true` will be returned.
+    /// state and the zone is not in maintenance mode. If a load has been
+    /// enqueued, it will be initiated (making the data storage busy), and
+    /// `true` will be returned.
     ///
     /// ## Panics
     ///

src/signer/zone.rs

@@ -261,8 +261,9 @@ impl SignerZoneHandle<'_> {
     /// Start a pending enqueued re-sign.
     ///
     /// This should be called when the zone state machine is in the waiting
-    /// state. If a re-sign has been enqueued, it will be initiated (making the
-    /// data storage busy), and `true` will be returned.
+    /// state and the zone is not in maintenance mode. If a re-sign has been
+    /// enqueued, it will be initiated (making the data storage busy), and
+    /// `true` will be returned.
     ///
     /// This method cannot initiate enqueued new-signing operations (see
     /// [`Self::enqueue_new_sign()`]); when a new-signing operation is enqueued,

src/zone/machine.rs

@@ -104,14 +104,10 @@ impl ZoneStateMachine {
 /// # Initiating operations
 impl<'a> ZoneHandle<'a> {
     pub(crate) fn try_start_load(&mut self) -> Option<LoadedZoneBuilder> {
-        // If we're in maintenance mode, then we don't start this operation.
-        // TODO: distinguish between a manual load and an automatic one.
-        if self.state.maintenance_mode {
-            return None;
-        }
-
-        let ZoneStateMachine::Waiting(_) = &self.state.machine else {
-            info!("Could not start load since an operation is in progress on the zone.");
+        if !self.state.ready_for_operation() {
+            info!(
+                "Could not start load since an operation is in progress on the zone or the zone is in maintenance mode."
+            );
             return None;
         };
 
@@ -138,13 +134,7 @@ impl<'a> ZoneHandle<'a> {
     }
 
     pub(crate) fn try_start_resign(&mut self) -> Option<SignedZoneBuilder> {
-        // If we're in maintenance mode, then we don't start this operation.
-        // TODO: distinguish between a manual resign and an automatic one.
-        if self.state.maintenance_mode {
-            return None;
-        }
-
-        let ZoneStateMachine::Waiting(_) = &self.state.machine else {
+        if !self.state.ready_for_operation() {
             info!("Could not start load since an operation is in progress on the zone.");
             return None;
         };

src/zone/mod.rs

@@ -425,6 +425,14 @@ impl ZoneState {
             .find(|item| item.event.is_of_type(typ) && (serial.is_none() || item.serial == serial))
     }
 
+    /// Whether the zone state is ready to start a new loading or signing operation
+    ///
+    /// This checks the maintenance mode and the zone state machine.
+    pub fn ready_for_operation(&self) -> bool {
+        // TODO: distinguish between a manual load/sign and an automatic one.
+        !self.maintenance_mode && matches!(&self.machine, ZoneStateMachine::Waiting(_))
+    }
+
     /// Get the most recent signed metadata for the zone.
     ///
     /// During restore the metadata for the currently published instance is

src/zone/state/mod.rs

@@ -85,6 +85,7 @@ impl Spec {
         match self {
             Self::V1(v1::Spec {
                 policy,
+                maintenance_mode,
                 instances,
                 source,
                 min_expiration,
@@ -135,6 +136,7 @@ impl Spec {
                     loader,
                     history,
                     persistence,
+                    maintenance_mode,
                     ..Default::default()
                 })
             }

src/zone/state/v1.rs

@@ -50,6 +50,12 @@ pub struct Spec {
     /// version of the policy that is not yet in use.
     pub policy: Option<PolicySpec>,
 
+    /// Whether the zone is in maintenance mode
+    ///
+    /// Maintenance mode means that Cascade won't start loading and signing
+    /// operations automatically.
+    pub maintenance_mode: bool,
+
     /// Instances of the zone.
     pub instances: InstancesSpec,
 
@@ -125,6 +131,7 @@ impl Spec {
     pub fn build(zone: &ZoneState) -> Self {
         Self {
             policy: zone.policy.as_ref().map(|p| PolicySpec::build(p)),
+            maintenance_mode: zone.maintenance_mode,
             instances: InstancesSpec::build(&zone.instances),
             source: ZoneLoadSourceSpec::build(&zone.loader.source),
             min_expiration: zone.min_expiration,

src/zone/storage.rs

@@ -38,7 +38,7 @@ use crate::{
     persistence::zone::IxfrZoneDiffs,
     server::{LoadedReviewServer, PublicationServer, SignedReviewServer},
     util::BackgroundTasks,
-    zone::{Zone, ZoneHandle, ZoneState, machine::ZoneStateMachine},
+    zone::{Zone, ZoneHandle, ZoneState},
 };
 
 //----------- StorageZoneHandle ------------------------------------------------
@@ -815,7 +815,7 @@ impl StorageZoneHandle<'_> {
         // loading a new instance.
 
         // Ensure a new operation can be started.
-        let ZoneStateMachine::Waiting(_) = &self.state.machine else {
+        if !self.state.ready_for_operation() {
             trace!("Ignoring `on_passive()` because the pipeline is busy");
             return;
         };