add genesis time in path chain loader

Author: ltitanb

config.example.toml

@@ -3,7 +3,7 @@
 
 # Chain spec ID. Supported values:
 # A network ID. Supported values: Mainnet, Holesky, Sepolia, Helder.
-# A path to a chain spec file, either in .json format (e.g., as returned by the beacon endpoint /eth/v1/config/spec), or in .yml format (see examples in tests/data).
+# A custom object, e.g., chain = { genesis_time_secs = 1695902400, path = "/path/to/spec.json" }, with a path to a chain spec file, either in .json format (e.g., as returned by the beacon endpoint /eth/v1/config/spec), or in .yml format (see examples in tests/data).
 # A custom object, e.g., chain = { genesis_time_secs = 1695902400, slot_time_secs = 12, genesis_fork_version = "0x01017000" }.
 chain = "Holesky"
 

configs/custom_chain.toml

@@ -0,0 +1,11 @@
+# PBS config with a custom chain spec file
+
+# genesis time in seconds needs to be specified
+chain = { genesis_time_secs = 100, path = "tests/data/holesky_spec.json" }
+
+[pbs]
+port = 18550
+
+[[relays]]
+id = "example-relay"
+url = "http://0xa1cec75a3f0661e99299274182938151e8433c61a19222347ea1313d839229cb4ce4e3e5aa2bdeb71c8fcf1b084963c2@abc.xyz"

crates/common/src/config/mod.rs

@@ -48,22 +48,34 @@ impl CommitBoostConfig {
     // When loading the config from the environment, it's important that every path
     // is replaced with the correct value if the config is loaded inside a container
     pub fn from_env_path() -> Result<Self> {
-        let config = if let Some(path) = load_optional_env_var(CHAIN_SPEC_ENV) {
-            // if the chain spec file is set, load it separately
-            let chain: Chain = load_chain_from_file(path.parse()?)?;
-            let rest_config: HelperConfig = load_file_from_env(CONFIG_ENV)?;
+        let helper_config: HelperConfig = load_file_from_env(CONFIG_ENV)?;
 
-            CommitBoostConfig {
-                chain,
-                relays: rest_config.relays,
-                pbs: rest_config.pbs,
-                modules: rest_config.modules,
-                signer: rest_config.signer,
-                metrics: rest_config.metrics,
-                logs: rest_config.logs,
+        let chain = match helper_config.chain {
+            ChainLoader::Path { path, genesis_time_secs } => {
+                // check if the file path is overridden by env var
+                let (slot_time_secs, genesis_fork_version) =
+                    if let Some(path) = load_optional_env_var(CHAIN_SPEC_ENV) {
+                        load_chain_from_file(path.parse()?)?
+                    } else {
+                        load_chain_from_file(path)?
+                    };
+                Chain::Custom { genesis_time_secs, slot_time_secs, genesis_fork_version }
             }
-        } else {
-            load_file_from_env(CONFIG_ENV)?
+            ChainLoader::Known(known) => Chain::from(known),
+            ChainLoader::Custom { genesis_time_secs, slot_time_secs, genesis_fork_version } => {
+                let genesis_fork_version: [u8; 4] = genesis_fork_version.as_ref().try_into()?;
+                Chain::Custom { genesis_time_secs, slot_time_secs, genesis_fork_version }
+            }
+        };
+
+        let config = CommitBoostConfig {
+            chain,
+            relays: helper_config.relays,
+            pbs: helper_config.pbs,
+            modules: helper_config.modules,
+            signer: helper_config.signer,
+            metrics: helper_config.metrics,
+            logs: helper_config.logs,
         };
 
         config.validate()?;
@@ -74,8 +86,8 @@ impl CommitBoostConfig {
     pub fn chain_spec_file(path: &str) -> Option<PathBuf> {
         match load_from_file::<ChainConfig>(path) {
             Ok(config) => {
-                if let ChainLoader::Path(path_buf) = config.chain {
-                    Some(path_buf)
+                if let ChainLoader::Path { path, genesis_time_secs: _ } = config.chain {
+                    Some(path)
                 } else {
                     None
                 }
@@ -94,6 +106,7 @@ struct ChainConfig {
 /// Helper struct to load the rest of the config
 #[derive(Deserialize)]
 struct HelperConfig {
+    chain: ChainLoader,
     relays: Vec<RelayConfig>,
     pbs: StaticPbsConfig,
     modules: Option<Vec<StaticModuleConfig>>,

crates/common/src/types.rs

@@ -163,8 +163,19 @@ impl From<KnownChain> for Chain {
 #[serde(untagged)]
 pub enum ChainLoader {
     Known(KnownChain),
-    Path(PathBuf),
-    Custom { genesis_time_secs: u64, slot_time_secs: u64, genesis_fork_version: Bytes },
+    Path {
+        /// Genesis time as returned in /eth/v1/beacon/genesis
+        genesis_time_secs: u64,
+        /// Path to the genesis spec, as returned by /eth/v1/config/spec
+        /// either in JSON or YAML format
+        path: PathBuf,
+    },
+    Custom {
+        /// Genesis time as returned in /eth/v1/beacon/genesis
+        genesis_time_secs: u64,
+        slot_time_secs: u64,
+        genesis_fork_version: Bytes,
+    },
 }
 
 impl Serialize for Chain {
@@ -199,7 +210,11 @@ impl<'de> Deserialize<'de> for Chain {
 
         match loader {
             ChainLoader::Known(known) => Ok(Chain::from(known)),
-            ChainLoader::Path(path) => load_chain_from_file(path).map_err(serde::de::Error::custom),
+            ChainLoader::Path { genesis_time_secs, path } => {
+                let (slot_time_secs, genesis_fork_version) =
+                    load_chain_from_file(path).map_err(serde::de::Error::custom)?;
+                Ok(Chain::Custom { genesis_time_secs, slot_time_secs, genesis_fork_version })
+            }
             ChainLoader::Custom { genesis_time_secs, slot_time_secs, genesis_fork_version } => {
                 let genesis_fork_version: [u8; 4] =
                     genesis_fork_version.as_ref().try_into().map_err(serde::de::Error::custom)?;
@@ -209,38 +224,25 @@ impl<'de> Deserialize<'de> for Chain {
     }
 }
 
-/// Load a chain config from a spec file, such as returned by
-/// /eth/v1/config/spec ref: https://ethereum.github.io/beacon-APIs/#/Config/getSpec
+/// Returns seconds_per_slot and genesis_fork_version from a spec, such as
+/// returned by /eth/v1/config/spec ref: https://ethereum.github.io/beacon-APIs/#/Config/getSpec
 /// Try to load two formats:
 /// - JSON as return the getSpec endpoint, either with or without the `data`
 ///   field
 /// - YAML as used e.g. in Kurtosis/Ethereum Package
-pub fn load_chain_from_file(path: PathBuf) -> eyre::Result<Chain> {
+pub fn load_chain_from_file(path: PathBuf) -> eyre::Result<(u64, [u8; 4])> {
     #[derive(Deserialize)]
     #[serde(rename_all = "UPPERCASE")]
     struct QuotedSpecFile {
-        #[serde(with = "serde_utils::quoted_u64")]
-        min_genesis_time: u64,
-        #[serde(with = "serde_utils::quoted_u64")]
-        genesis_delay: u64,
         #[serde(with = "serde_utils::quoted_u64")]
         seconds_per_slot: u64,
         genesis_fork_version: Bytes,
     }
 
     impl QuotedSpecFile {
-        fn to_chain(&self) -> eyre::Result<Chain> {
+        fn to_chain(&self) -> eyre::Result<(u64, [u8; 4])> {
             let genesis_fork_version: [u8; 4] = self.genesis_fork_version.as_ref().try_into()?;
-
-            Ok(Chain::Custom {
-                // note that this can be wrong, (e.g. it's wrong in mainnet). The correct
-                // value should come from /eth/v1/beacon/genesis
-                // more info here: https://kb.beaconcha.in/ethereum-staking/the-genesis-event
-                // FIXME
-                genesis_time_secs: self.min_genesis_time + self.genesis_delay,
-                slot_time_secs: self.seconds_per_slot,
-                genesis_fork_version,
-            })
+            Ok((self.seconds_per_slot, genesis_fork_version))
         }
     }
 
@@ -252,21 +254,14 @@ pub fn load_chain_from_file(path: PathBuf) -> eyre::Result<Chain> {
     #[derive(Deserialize)]
     #[serde(rename_all = "UPPERCASE")]
     struct SpecFile {
-        min_genesis_time: u64,
-        genesis_delay: u64,
         seconds_per_slot: u64,
         genesis_fork_version: u32,
     }
 
     impl SpecFile {
-        fn to_chain(&self) -> Chain {
+        fn to_chain(&self) -> (u64, [u8; 4]) {
             let genesis_fork_version: [u8; 4] = self.genesis_fork_version.to_be_bytes();
-
-            Chain::Custom {
-                genesis_time_secs: self.min_genesis_time + self.genesis_delay,
-                slot_time_secs: self.seconds_per_slot,
-                genesis_fork_version,
-            }
+            (self.seconds_per_slot, genesis_fork_version)
         }
     }