Add option to download checkpoint sync beacon state at custom slot

fork_choice_control/src/checkpoint_sync.rs

@@ -13,20 +13,28 @@ use types::{
     combined::{BeaconState, SignedBeaconBlock},
     config::Config,
     nonstandard::FinalizedCheckpoint,
-    phase0::{consts::GENESIS_EPOCH, primitives::H256},
+    phase0::{
+        consts::GENESIS_EPOCH,
+        primitives::{Slot, H256},
+    },
     preset::Preset,
     redacting_url::RedactingUrl,
     traits::SignedBeaconBlock as _,
 };
 
-pub async fn load_finalized_from_remote<P: Preset>(
+pub async fn load_from_remote<P: Preset>(
     config: &Config,
     client: &Client,
     url: &RedactingUrl,
+    checkpoint_slot: Option<Slot>,
 ) -> Result<FinalizedCheckpoint<P>> {
     info!("performing checkpoint sync from {url}…");
 
-    let mut block = fetch_block(config, client, url, BlockId::Finalized)
+    let block_id = checkpoint_slot
+        .map(BlockId::Slot)
+        .unwrap_or(BlockId::Finalized);
+
+    let mut block = fetch_block(config, client, url, block_id)
         .await?
         .ok_or(Error::NoFinalizedBlock)?;
 

fork_choice_control/src/storage.rs

@@ -41,10 +41,12 @@ pub enum StateLoadStrategy<P: Preset> {
     Auto {
         state_slot: Option<Slot>,
         checkpoint_sync_url: Option<RedactingUrl>,
+        checkpoint_sync_slot: Option<Slot>,
         anchor_checkpoint_provider: AnchorCheckpointProvider<P>,
     },
     Remote {
         checkpoint_sync_url: RedactingUrl,
+        checkpoint_sync_slot: Option<Slot>,
     },
     Anchor {
         block: Arc<SignedBeaconBlock<P>>,
@@ -108,6 +110,7 @@ impl<P: Preset> Storage<P> {
             StateLoadStrategy::Auto {
                 state_slot,
                 checkpoint_sync_url,
+                checkpoint_sync_slot,
                 anchor_checkpoint_provider,
             } => 'block: {
                 // Attempt to load local state first: either latest or from specified slot.
@@ -124,9 +127,14 @@ impl<P: Preset> Storage<P> {
                             info!("anchor checkpoint is already loaded from remote checkpoint sync server");
                             Ok(checkpoint)
                         } else {
-                            checkpoint_sync::load_finalized_from_remote(&self.config, client, &url)
-                                .await
-                                .context(Error::CheckpointSyncFailed)
+                            checkpoint_sync::load_from_remote(
+                                &self.config,
+                                client,
+                                &url,
+                                checkpoint_sync_slot,
+                            )
+                            .await
+                            .context(Error::CheckpointSyncFailed)
                         };
 
                         match result {
@@ -174,15 +182,16 @@ impl<P: Preset> Storage<P> {
             }
             StateLoadStrategy::Remote {
                 checkpoint_sync_url,
+                checkpoint_sync_slot,
             } => {
-                let FinalizedCheckpoint { block, state } =
-                    checkpoint_sync::load_finalized_from_remote(
-                        &self.config,
-                        client,
-                        &checkpoint_sync_url,
-                    )
-                    .await
-                    .context(Error::CheckpointSyncFailed)?;
+                let FinalizedCheckpoint { block, state } = checkpoint_sync::load_from_remote(
+                    &self.config,
+                    client,
+                    &checkpoint_sync_url,
+                    checkpoint_sync_slot,
+                )
+                .await
+                .context(Error::CheckpointSyncFailed)?;
 
                 anchor_block = block;
                 anchor_state = state;

grandine/src/grandine_args.rs

@@ -259,6 +259,11 @@ struct BeaconNodeOptions {
     #[clap(long)]
     checkpoint_sync_url: Option<RedactingUrl>,
 
+    /// Load checkpoint state at specified slot instead of recent finalized one. Requires --checkpoint-sync-url
+    /// [default: None]
+    #[clap(long, requires = "checkpoint_sync_url")]
+    checkpoint_sync_slot: Option<Slot>,
+
     /// Force checkpoint sync. Requires --checkpoint-sync-url
     /// [default: disabled]
     #[clap(long, requires = "checkpoint_sync_url")]
@@ -913,6 +918,7 @@ impl GrandineArgs {
             max_empty_slots,
             max_events,
             checkpoint_sync_url,
+            checkpoint_sync_slot,
             eth1_rpc_urls,
             force_checkpoint_sync,
             data_dir,
@@ -1287,6 +1293,7 @@ impl GrandineArgs {
             genesis_state_file,
             genesis_state_download_url,
             checkpoint_sync_url,
+            checkpoint_sync_slot,
             force_checkpoint_sync,
             back_sync_enabled,
             eth1_rpc_urls,

grandine/src/grandine_config.rs

@@ -35,6 +35,7 @@ pub struct GrandineConfig {
     pub genesis_state_file: Option<PathBuf>,
     pub genesis_state_download_url: Option<RedactingUrl>,
     pub checkpoint_sync_url: Option<RedactingUrl>,
+    pub checkpoint_sync_slot: Option<Slot>,
     pub force_checkpoint_sync: bool,
     pub back_sync_enabled: bool,
     pub eth1_rpc_urls: Vec<RedactingUrl>,

grandine/src/main.rs

@@ -86,6 +86,7 @@ struct Context {
     validator_api_config: Option<ValidatorApiConfig>,
     validator_config: Arc<ValidatorConfig>,
     checkpoint_sync_url: Option<RedactingUrl>,
+    checkpoint_sync_slot: Option<Slot>,
     force_checkpoint_sync: bool,
     back_sync_enabled: bool,
     eth1_rpc_urls: Vec<RedactingUrl>,
@@ -169,6 +170,7 @@ impl Context {
             validator_api_config,
             validator_config,
             checkpoint_sync_url,
+            checkpoint_sync_slot,
             force_checkpoint_sync,
             back_sync_enabled,
             eth1_rpc_urls,
@@ -272,11 +274,13 @@ impl Context {
                     "the requires attribute for force_checkpoint_sync \
                      ensures checkpoint_sync_url is present",
                 ),
+                checkpoint_sync_slot,
             }
         } else {
             StateLoadStrategy::Auto {
                 state_slot,
                 checkpoint_sync_url,
+                checkpoint_sync_slot,
                 anchor_checkpoint_provider: anchor_checkpoint_provider.clone(),
             }
         };
@@ -359,6 +363,7 @@ fn try_main() -> Result<()> {
         genesis_state_file,
         genesis_state_download_url,
         checkpoint_sync_url,
+        checkpoint_sync_slot,
         force_checkpoint_sync,
         back_sync_enabled,
         eth1_rpc_urls,
@@ -526,6 +531,7 @@ fn try_main() -> Result<()> {
         validator_api_config,
         validator_config,
         checkpoint_sync_url,
+        checkpoint_sync_slot,
         force_checkpoint_sync,
         back_sync_enabled,
         eth1_rpc_urls,