sim-cli: add latency interceptor option in cli

Author: elnosh

sim-cli/src/main.rs

@@ -1,6 +1,9 @@
+use std::sync::Arc;
+
 use clap::Parser;
 use log::LevelFilter;
 use sim_cli::parsing::{create_simulation, create_simulation_with_network, parse_sim_params, Cli};
+use simln_lib::{latency_interceptor::LatencyIntercepor, sim_node::Interceptor};
 use simple_logger::SimpleLogger;
 use tokio_util::task::TaskTracker;
 
@@ -29,7 +32,13 @@ async fn main() -> anyhow::Result<()> {
     let (sim, validated_activities) = if sim_params.sim_network.is_empty() {
         create_simulation(&cli, &sim_params, tasks.clone()).await?
     } else {
-        create_simulation_with_network(&cli, &sim_params, tasks.clone()).await?
+        let latency = cli.latency_ms.unwrap_or(0);
+        let interceptors = if latency > 0 {
+            vec![Arc::new(LatencyIntercepor::new_poisson(latency as f32)?) as Arc<dyn Interceptor>]
+        } else {
+            vec![]
+        };
+        create_simulation_with_network(&cli, &sim_params, tasks.clone(), interceptors).await?
     };
     let sim2 = sim.clone();
 

sim-cli/src/parsing.rs

@@ -5,7 +5,8 @@ use log::LevelFilter;
 use serde::{Deserialize, Serialize};
 use simln_lib::clock::SimulationClock;
 use simln_lib::sim_node::{
-    ln_node_from_graph, populate_network_graph, ChannelPolicy, SimGraph, SimulatedChannel,
+    ln_node_from_graph, populate_network_graph, ChannelPolicy, Interceptor, SimGraph,
+    SimulatedChannel,
 };
 use simln_lib::{
     cln, cln::ClnNode, eclair, eclair::EclairNode, lnd, lnd::LndNode, serializers,
@@ -87,6 +88,10 @@ pub struct Cli {
     /// simulated nodes.
     #[clap(long)]
     pub speedup_clock: Option<u16>,
+    /// Latency to optionally introduce for payments in a simulated network expressed in
+    /// milliseconds.
+    #[clap(long)]
+    pub latency_ms: Option<u32>,
 }
 
 impl Cli {
@@ -112,6 +117,12 @@ impl Cli {
             ));
         }
 
+        if !sim_params.nodes.is_empty() && self.latency_ms.is_some() {
+            return Err(anyhow!(
+                "Latency for payments is only allowed when running on a simulated network"
+            ));
+        }
+
         Ok(())
     }
 }
@@ -217,6 +228,7 @@ pub async fn create_simulation_with_network(
     cli: &Cli,
     sim_params: &SimParams,
     tasks: TaskTracker,
+    interceptors: Vec<Arc<dyn Interceptor>>,
 ) -> Result<(Simulation<SimulationClock>, Vec<ActivityDefinition>), anyhow::Error> {
     let cfg: SimulationCfg = SimulationCfg::try_from(cli)?;
     let SimParams {
@@ -246,7 +258,7 @@ pub async fn create_simulation_with_network(
         SimGraph::new(
             channels.clone(),
             tasks.clone(),
-            vec![],
+            interceptors,
             (shutdown_trigger.clone(), shutdown_listener.clone()),
         )
         .map_err(|e| SimulationError::SimulatedNetworkError(format!("{:?}", e)))?,