Add CLI flags to delay publishing for edge case testing on PeerDAS devnets

[jimmygchen]

It would be useful to add some CLI flags on the beacon node to test out some unhappy cases on PeerDAS devnets, for example:

• --delay-block-publishing <seconds>
• --delay-data-column-publishing <seconds>

These can be used for testing late publishing and recovery from missed/orphaned blocks on devnets.

These should be hidden flags and must be explicitly state as testing only flags.

[kamuik16]

Hey @jimmygchen, do you mind if I raise a PR and help out with this issue?

[jimmygchen]

Hey Krishang 👋 how is it going?
Sure, that would be amazing!

[kamuik16]

Hey, thanks, just to make sure, I need to add the --delay-block-publishing & --delay-data-column-publishing flags in beacon_node/src/cli.rs. Then the values I get from these flags should be used to set which of the values?

[jimmygchen]

Yep that's correct - and we want to use these config values (if present) to delay block / data column publishing, the publish logic can be found in this function:

lighthouse/beacon_node/http_api/src/publish_blocks.rs

Lines 76 to 87 in e98209d

	/// Handles a request from the HTTP API for full blocks.
	#[allow(clippy::too_many_arguments)]
	pub async fn publish_block<T: BeaconChainTypes, B: IntoGossipVerifiedBlock<T>>(
	block_root: Option<Hash256>,
	provenanced_block: ProvenancedBlock<T, B>,
	chain: Arc<BeaconChain<T>>,
	network_tx: &UnboundedSender<NetworkMessage<T::EthSpec>>,
	log: Logger,
	validation_level: BroadcastValidation,
	duplicate_status_code: StatusCode,
	network_globals: Arc<NetworkGlobals<T::EthSpec>>,
	) -> Result<Response, Rejection> {

In this function you have access to the config parameters via chain.config.

[jimmygchen]

Completed in #6947