Feat: add new --advertise-false-custody-group-count cli flag for PeerDAS testing

beacon_node/lighthouse_network/src/config.rs

@@ -148,6 +148,9 @@ pub struct Config {
     /// Configuration for the minimum message size for which IDONTWANT messages are send in the mesh.
     /// Lower the value reduces the optimization effect of the IDONTWANT messages.
     pub idontwant_message_size_threshold: usize,
+
+    /// Advertise a false custody group count in metadata.
+    pub advertise_false_custody_group_count: Option<u64>,
 }
 
 impl Config {
@@ -372,6 +375,7 @@ impl Default for Config {
             invalid_block_storage: None,
             inbound_rate_limiter_config: None,
             idontwant_message_size_threshold: DEFAULT_IDONTWANT_MESSAGE_SIZE_THRESHOLD,
+            advertise_false_custody_group_count: None,
         }
     }
 }

beacon_node/lighthouse_network/src/service/mod.rs

@@ -199,8 +199,13 @@ impl<E: EthSpec> Network<E> {
 
         // Construct the metadata
         let custody_group_count = ctx.chain_spec.is_peer_das_scheduled().then(|| {
-            ctx.chain_spec
-                .custody_group_count(config.subscribe_all_data_column_subnets)
+            // Use the false custody group count if specified, otherwise use the normal one
+            if let Some(false_count) = config.advertise_false_custody_group_count {
+                false_count
+            } else {
+                ctx.chain_spec
+                    .custody_group_count(config.subscribe_all_data_column_subnets)
+            }
         });
         let meta_data = utils::load_or_build_metadata(&config.network_dir, custody_group_count);
         let seq_number = *meta_data.seq_number();

beacon_node/src/cli.rs

@@ -68,6 +68,20 @@ pub fn cli_app() -> Command {
                 .hide(true)
                 .display_order(0)
         )
+        .arg(
+            // TODO(das): remove this before PeerDAS release
+            Arg::new("advertise-false-custody-group-count")
+                .long("advertise-false-custody-group-count")
+                .action(ArgAction::Set)
+                .help_heading(FLAG_HEADER)
+                .help("TESTING ONLY: Advertise a false custody group count in metadata. Makes \
+                        peers think this node custodies more columns than it actually does. \
+                        It's used to override the actual custody group count when building node metadata, \
+                        but only when PeerDAS is scheduled and the value is within valid range.
+                        DO NOT USE IN PRODUCTION.")
+                .hide(true)
+                .display_order(0)
+        )
         .arg(
             Arg::new("enable-sampling")
                 .long("enable-sampling")

beacon_node/src/config.rs

@@ -30,7 +30,7 @@ use std::str::FromStr;
 use std::time::Duration;
 use tracing::{error, info, warn};
 use types::graffiti::GraffitiString;
-use types::{Checkpoint, Epoch, EthSpec, Hash256, PublicKeyBytes};
+use types::{ChainSpec, Checkpoint, Epoch, EthSpec, Hash256, PublicKeyBytes};
 
 const PURGE_DB_CONFIRMATION: &str = "confirm";
 
@@ -108,7 +108,12 @@ pub fn get_config<E: EthSpec>(
 
     let data_dir_ref = client_config.data_dir().clone();
 
-    set_network_config(&mut client_config.network, cli_args, &data_dir_ref)?;
+    set_network_config(
+        &mut client_config.network,
+        cli_args,
+        &data_dir_ref,
+        Some(spec),
+    )?;
 
     /*
      * Staking flag
@@ -1144,6 +1149,7 @@ pub fn set_network_config(
     config: &mut NetworkConfig,
     cli_args: &ArgMatches,
     data_dir: &Path,
+    spec: Option<&ChainSpec>,
 ) -> Result<(), String> {
     // If a network dir has been specified, override the `datadir` definition.
     if let Some(dir) = cli_args.get_one::<String>("network-dir") {
@@ -1170,6 +1176,20 @@ pub fn set_network_config(
 
     config.set_listening_addr(parse_listening_addresses(cli_args)?);
 
+    if let Some(false_custody_group_count) =
+        clap_utils::parse_optional(cli_args, "advertise-false-custody-group-count")?
+    {
+        if let Some(spec) = spec {
+            if false_custody_group_count > spec.number_of_custody_groups {
+                return Err(format!(
+                    "advertise-false-custody-group-count ({}) exceeds number_of_custody_groups ({})",
+                    false_custody_group_count, spec.number_of_custody_groups
+                ));
+            }
+        }
+        config.advertise_false_custody_group_count = Some(false_custody_group_count);
+    }
+
     // A custom target-peers command will overwrite the --proposer-only default.
     if let Some(target_peers_str) = cli_args.get_one::<String>("target-peers") {
         config.target_peers = target_peers_str

boot_node/src/config.rs

@@ -53,7 +53,9 @@ impl<E: EthSpec> BootNodeConfig<E> {
 
         let mut network_config = NetworkConfig::default();
 
-        set_network_config(&mut network_config, matches, &data_dir)?;
+        let spec = eth2_network_config.chain_spec::<E>()?;
+
+        set_network_config(&mut network_config, matches, &data_dir, Some(&spec))?;
 
         // Set the Enr Discovery ports to the listening ports if not present.
         if let Some(listening_addr_v4) = network_config.listen_addrs().v4() {

lighthouse/tests/beacon_node.rs

@@ -2033,6 +2033,20 @@ fn malicious_withhold_count_flag() {
         .with_config(|config| assert_eq!(config.chain.malicious_withhold_count, 128));
 }
 
+#[test]
+fn advertise_false_custody_group_count_flag() {
+    CommandLineTest::new()
+        .flag("advertise-false-custody-group-count", Some("128"))
+        .run_with_zero_port()
+        .with_config(|config| {
+            let network_config = &config.network;
+            assert_eq!(
+                network_config.advertise_false_custody_group_count,
+                Some(128)
+            );
+        });
+}
+
 // Tests for Slasher flags.
 // Using `--slasher-max-db-size` to work around https://github.com/sigp/lighthouse/issues/2342
 #[test]