Ensure custody backfill sync couples all responses before importing (#8339)

Custody backfill sync has a bug when we request columns from more than one peer per batch. The fix here ensures we wait for all requests to be completed before performing verification and importing the responses.

I've also added an endpoint `lighthouse/custody/backfill` that resets a nodes earliest available data column to the current epoch so that custody backfill can be triggered. This endpoint is needed to rescue any nodes that may have missing columns due to the custody backfill sync bug without requiring a full re-sync.


  


Co-Authored-By: Eitan Seri- Levi <eserilev@gmail.com>

Co-Authored-By: Eitan Seri-Levi <eserilev@ucsc.edu>

Co-Authored-By: Jimmy Chen <jchen.tc@gmail.com>

Co-Authored-By: Michael Sproul <michaelsproul@users.noreply.github.com>

beacon_node/http_api/src/test_utils.rs

@@ -1,6 +1,7 @@
 use crate::{Config, Context};
 use beacon_chain::{
     BeaconChain, BeaconChainTypes,
+    custody_context::NodeCustodyType,
     test_utils::{BeaconChainHarness, BoxedMutator, Builder, EphemeralHarnessType},
 };
 use beacon_processor::{
@@ -67,6 +68,20 @@ impl<E: EthSpec> InteractiveTester<E> {
             None,
             Config::default(),
             true,
+            NodeCustodyType::Fullnode,
+        )
+        .await
+    }
+
+    pub async fn new_supernode(spec: Option<ChainSpec>, validator_count: usize) -> Self {
+        Self::new_with_initializer_and_mutator(
+            spec,
+            validator_count,
+            None,
+            None,
+            Config::default(),
+            true,
+            NodeCustodyType::Supernode,
         )
         .await
     }
@@ -78,6 +93,7 @@ impl<E: EthSpec> InteractiveTester<E> {
         mutator: Option<Mutator<E>>,
         config: Config,
         use_mock_builder: bool,
+        node_custody_type: NodeCustodyType,
     ) -> Self {
         let mut harness_builder = BeaconChainHarness::builder(E::default())
             .spec_or_default(spec.map(Arc::new))
@@ -93,6 +109,8 @@ impl<E: EthSpec> InteractiveTester<E> {
                 .fresh_ephemeral_store()
         };
 
+        harness_builder = harness_builder.node_custody_type(node_custody_type);
+
         // Add a mutator for the beacon chain builder which will be called in
         // `HarnessBuilder::build`.
         if let Some(mutator) = mutator {