feat: build valid fallback payload with Nethermind

bolt-sidecar/src/builder/fallback/engine_hinter.rs

@@ -20,6 +20,9 @@ use crate::{
 
 use super::engine_hints::parse_hint_from_engine_response;
 
+/// The maximum number of hint iterations to try before giving up.
+const MAX_HINT_ITERATIONS: u64 = 20;
+
 /// The [EngineHinter] is responsible for gathering "hints" from the
 /// engine API error responses to complete the sealed block.
 ///
@@ -58,7 +61,6 @@ impl EngineHinter {
 
         // Loop until we get a valid payload from the engine API. On each iteration,
         // we build a new block header with the hints from the context and fetch the next hint.
-        let max_iterations = 20;
         let mut iteration = 0;
         loop {
             debug!(%iteration, "Fetching hint from engine API");
@@ -76,6 +78,7 @@ impl EngineHinter {
 
             // attempt to fetch the next hint from the engine API payload response
             let hint = self.next_hint(exec_payload, &ctx).await?;
+            debug!(?hint, "Received hint from engine API");
 
             if matches!(hint, EngineApiHint::ValidPayload) {
                 return Ok(sealed_block);
@@ -85,8 +88,8 @@ impl EngineHinter {
             ctx.hints.populate_new(hint);
 
             iteration += 1;
-            if iteration >= max_iterations {
-                return Err(BuilderError::ExceededMaxHintIterations(max_iterations));
+            if iteration >= MAX_HINT_ITERATIONS {
+                return Err(BuilderError::ExceededMaxHintIterations(MAX_HINT_ITERATIONS));
             }
         }
     }
@@ -121,7 +124,8 @@ impl EngineHinter {
         // Parse the hint from the engine API response, based on the EL client code
         let Some(hint) = parse_hint_from_engine_response(ctx.el_client_code, &validation_error)?
         else {
-            return Err(BuilderError::FailedToParseHintsFromEngine);
+            let el_name = ctx.el_client_code.client_name().to_string();
+            return Err(BuilderError::FailedToParseHintsFromEngine(el_name));
         };
 
         Ok(hint)

bolt-sidecar/src/builder/fallback/engine_hints/geth.rs

@@ -1,9 +1,15 @@
 use alloy::primitives::{Bloom, B256};
 use hex::FromHex;
+use lazy_static::lazy_static;
 use regex::Regex;
 
 use crate::builder::{fallback::engine_hinter::EngineApiHint, BuilderError};
 
+lazy_static! {
+    /// Capture either the "local" or "got" value from the error message
+    static ref REGEX: Regex = Regex::new(r"(?:local:|got) ([0-9a-zA-Z]+)").expect("valid regex");
+}
+
 /// Parse a hinted value from the engine response.
 /// An example error message from the engine API looks like this:
 ///
@@ -22,10 +28,7 @@ use crate::builder::{fallback::engine_hinter::EngineApiHint, BuilderError};
 /// - [ValidateState](<https://github.com/ethereum/go-ethereum/blob/9298d2db884c4e3f9474880e3dcfd080ef9eacfa/core/block_validator.go#L122-L151>)
 /// - [Blockhash Mismatch](<https://github.com/ethereum/go-ethereum/blob/9298d2db884c4e3f9474880e3dcfd080ef9eacfa/beacon/engine/types.go#L253-L256>)
 pub fn parse_geth_engine_error_hint(error: &str) -> Result<Option<EngineApiHint>, BuilderError> {
-    // Capture either the "local" or "got" value from the error message
-    let re = Regex::new(r"(?:local:|got) ([0-9a-zA-Z]+)").expect("valid regex");
-
-    let raw_hint_value = match re.captures(error).and_then(|cap| cap.get(1)) {
+    let raw_hint_value = match REGEX.captures(error).and_then(|cap| cap.get(1)) {
         Some(matched) => matched.as_str().to_string(),
         None => return Ok(None),
     };

bolt-sidecar/src/builder/fallback/engine_hints/mod.rs

@@ -21,8 +21,8 @@ pub fn parse_hint_from_engine_response(
 ) -> Result<Option<EngineApiHint>, BuilderError> {
     match client {
         ClientCode::GE => geth::parse_geth_engine_error_hint(error),
-        // TODO: Add Nethermind engine hints parsing
-        // ClientCode::NM => nethermind::parse_nethermind_engine_error_hint(error),
+        ClientCode::NM => nethermind::parse_nethermind_engine_error_hint(error),
+
         _ => {
             error!("Unsupported fallback execution client: {}", client.client_name());
             Err(BuilderError::UnsupportedEngineClient(client))

bolt-sidecar/src/builder/fallback/engine_hints/nethermind.rs

@@ -1,7 +1,15 @@
-use tracing::warn;
+use alloy::primitives::{Bloom, B256};
+use hex::FromHex;
+use lazy_static::lazy_static;
+use regex::Regex;
 
 use crate::builder::{fallback::engine_hinter::EngineApiHint, BuilderError};
 
+lazy_static! {
+    /// Capture the "got" value from the error message
+    static ref REGEX: Regex = Regex::new(r"got ([0-9a-zA-Z]+)").expect("valid regex");
+}
+
 /// Parse a hinted value from the engine response.
 /// An example error message from the engine API looks like this:
 ///
@@ -11,17 +19,30 @@ use crate::builder::{fallback::engine_hinter::EngineApiHint, BuilderError};
 ///     "id": 1,
 ///     "error": {
 ///         "code":-32000,
-///          "message": "local: blockhash mismatch: got 0x... expected 0x..."
+///          "message": "HeaderGasUsedMismatch: Gas used in header does not match calculated. Expected 0, got 21000"
 ///     }
 /// }
 /// ```
-// TODO: implement hints parsing
-// TODO: remove dead_code attribute
-#[allow(dead_code)]
 pub fn parse_nethermind_engine_error_hint(
     error: &str,
 ) -> Result<Option<EngineApiHint>, BuilderError> {
-    warn!(%error, "Nethermind engine error hint parsing is not implemented");
+    let raw_hint_value = match REGEX.captures(error).and_then(|cap| cap.get(1)) {
+        Some(matched) => matched.as_str().to_string(),
+        None => return Ok(None),
+    };
+
+    // Match the hint value to the corresponding hint type based on other parts of the error message
+    if error.contains("InvalidHeaderHash") {
+        return Ok(Some(EngineApiHint::BlockHash(B256::from_hex(raw_hint_value)?)));
+    } else if error.contains("HeaderGasUsedMismatch") {
+        return Ok(Some(EngineApiHint::GasUsed(raw_hint_value.parse()?)));
+    } else if error.contains("InvalidStateRoot") {
+        return Ok(Some(EngineApiHint::StateRoot(B256::from_hex(raw_hint_value)?)));
+    } else if error.contains("InvalidReceiptsRoot") {
+        return Ok(Some(EngineApiHint::ReceiptsRoot(B256::from_hex(raw_hint_value)?)));
+    } else if error.contains("InvalidLogsBloom") {
+        return Ok(Some(EngineApiHint::LogsBloom(Bloom::from_hex(&raw_hint_value)?)));
+    };
 
     Ok(None)
 }

bolt-sidecar/src/builder/fallback/payload_builder.rs

@@ -144,9 +144,8 @@ impl FallbackPayloadBuilder {
 mod tests {
     use std::time::{SystemTime, UNIX_EPOCH};
 
-    use alloy::consensus::constants;
     use alloy::{
-        consensus::proofs,
+        consensus::{constants, proofs},
         eips::eip2718::{Decodable2718, Encodable2718},
         network::{EthereumWallet, TransactionBuilder},
         primitives::{hex, Address},
@@ -195,9 +194,9 @@ mod tests {
         let raw_encoded = tx_signed.encoded_2718();
         let tx_signed_reth = TransactionSigned::decode_2718(&mut raw_encoded.as_slice())?;
 
-        let slot = genesis_time
-            + (SystemTime::now().duration_since(UNIX_EPOCH)?.as_secs() / cfg.chain.slot_time())
-            + 1;
+        let slot = genesis_time +
+            (SystemTime::now().duration_since(UNIX_EPOCH)?.as_secs() / cfg.chain.slot_time()) +
+            1;
 
         let block = builder.build_fallback_payload(slot, &[tx_signed_reth]).await?;
 

bolt-sidecar/src/builder/mod.rs

@@ -66,8 +66,8 @@ pub enum BuilderError {
     InvalidTransactions(String),
     #[error("Got an unexpected response from engine_newPayload query: {0}")]
     UnexpectedPayloadStatus(PayloadStatusEnum),
-    #[error("Failed to parse any hints from engine API validation error")]
-    FailedToParseHintsFromEngine,
+    #[error("Failed to parse any hints from engine API validation error (client: {0})")]
+    FailedToParseHintsFromEngine(String),
     #[error("Unsupported engine hint: {0}")]
     UnsupportedEngineHint(String),
     #[error("Unsupported engine client: {0}")]

bolt-sidecar/src/chain_io/manager.rs

@@ -1,3 +1,5 @@
+use std::time::Duration;
+
 use alloy::{
     contract::Error,
     primitives::Address,
@@ -9,15 +11,14 @@ use ethereum_consensus::primitives::BlsPublicKey;
 use eyre::{bail, Context};
 use reqwest::{Client, Url};
 use serde::Serialize;
-
 use tracing::{debug, warn};
+
 use BoltManagerContract::{
     BoltManagerContractErrors, BoltManagerContractInstance, ProposerStatus, ValidatorDoesNotExist,
 };
 
-use crate::config::chain::Chain;
-
 use super::utils::{self, CompressedHash};
+use crate::config::chain::Chain;
 
 /// Maximum number of keys to fetch from the EL node in a single query.
 const MAX_CHUNK_SIZE: usize = 100;
@@ -86,15 +87,8 @@ impl BoltManager {
                         // `retry_with_backoff_if` is not used here because we need to check
                         // that the error is retryable.
                         if transport_err.to_string().contains("error sending request for url") {
-                            warn!(
-                                "Retryable transport error when connecting to EL node: {}",
-                                transport_err
-                            );
-                            // Crude increasing backoff
-                            tokio::time::sleep(std::time::Duration::from_millis(
-                                100 * retries as u64,
-                            ))
-                            .await;
+                            warn!("Transport error when connecting to EL node: {}", transport_err);
+                            tokio::time::sleep(Duration::from_millis(100 * retries as u64)).await;
                             continue;
                         }
                         warn!(
@@ -108,9 +102,7 @@ impl BoltManager {
                         let decoded_error = utils::try_parse_contract_error(err)
                             .wrap_err("Failed to fetch proposer statuses from EL client")?;
 
-                        bail!(
-                            generate_bolt_manager_error(decoded_error, commitment_signer_pubkey,)
-                        );
+                        bail!(generate_bolt_manager_error(decoded_error, commitment_signer_pubkey));
                     }
                 }
             };
@@ -226,8 +218,7 @@ sol! {
 #[cfg(test)]
 mod tests {
     use ::hex::FromHex;
-    use alloy::hex;
-    use alloy::primitives::Address;
+    use alloy::{hex, primitives::Address};
     use alloy_node_bindings::Anvil;
     use ethereum_consensus::primitives::BlsPublicKey;
     use reqwest::Url;
@@ -268,8 +259,8 @@ mod tests {
                     .as_ref()).expect("valid bls public key")];
         let res = manager.verify_validator_pubkeys(keys.clone(), commitment_signer_pubkey).await;
         assert!(
-            res.unwrap_err().to_string()
-                == generate_operator_keys_mismatch_error(
+            res.unwrap_err().to_string() ==
+                generate_operator_keys_mismatch_error(
                     pubkey_hash(&keys[0]),
                     commitment_signer_pubkey,
                     operator
@@ -317,8 +308,8 @@ mod tests {
         let result = manager.verify_validator_pubkeys(keys.clone(), commitment_signer_pubkey).await;
 
         assert!(
-            result.unwrap_err().to_string()
-                == generate_operator_keys_mismatch_error(
+            result.unwrap_err().to_string() ==
+                generate_operator_keys_mismatch_error(
                     pubkey_hash(&keys[0]),
                     commitment_signer_pubkey,
                     operator