core: make node spawning fallible

testing-framework/core/src/nodes/common/node.rs

@@ -1,4 +1,5 @@
 use std::{
+    io,
     net::SocketAddr,
     path::{Path, PathBuf},
     process::{Child, Command, Stdio},
@@ -26,6 +27,37 @@ const STARTUP_TIMEOUT: Duration = Duration::from_secs(60);
 pub type NodeAddresses = (SocketAddr, Option<SocketAddr>);
 pub type PreparedNodeConfig<T> = (TempDir, T, SocketAddr, Option<SocketAddr>);
 
+#[derive(Debug, thiserror::Error)]
+pub enum SpawnNodeError {
+    #[error("failed to create node tempdir: {source}")]
+    TempDir {
+        #[source]
+        source: io::Error,
+    },
+    #[error("failed to prepare node recovery paths: {source}")]
+    RecoveryPaths {
+        #[source]
+        source: io::Error,
+    },
+    #[error("failed to write node config at {path}: {source}")]
+    WriteConfig {
+        path: PathBuf,
+        #[source]
+        source: io::Error,
+    },
+    #[error("failed to spawn node process '{binary}': {source}")]
+    Spawn {
+        binary: PathBuf,
+        #[source]
+        source: io::Error,
+    },
+    #[error("node did not become ready before timeout: {source}")]
+    Readiness {
+        #[source]
+        source: tokio::time::error::Elapsed,
+    },
+}
+
 /// Minimal interface to apply common node setup.
 pub trait NodeConfigCommon {
     fn set_logger(&mut self, logger: LoggerLayer);
@@ -92,14 +124,14 @@ pub fn prepare_node_config<T: NodeConfigCommon>(
     mut config: T,
     log_prefix: &str,
     enable_logging: bool,
-) -> PreparedNodeConfig<T> {
-    let dir = create_tempdir().expect("tempdir");
+) -> Result<PreparedNodeConfig<T>, SpawnNodeError> {
+    let dir = create_tempdir().map_err(|source| SpawnNodeError::TempDir { source })?;
 
     debug!(dir = %dir.path().display(), log_prefix, enable_logging, "preparing node config");
 
     // Ensure recovery files/dirs exist so services that persist state do not fail
     // on startup.
-    let _ = ensure_recovery_paths(dir.path());
+    ensure_recovery_paths(dir.path()).map_err(|source| SpawnNodeError::RecoveryPaths { source })?;
 
     if enable_logging {
         configure_logging(dir.path(), log_prefix, |file_cfg| {
@@ -112,7 +144,7 @@ pub fn prepare_node_config<T: NodeConfigCommon>(
 
     debug!(addr = %addr, testing_addr = ?testing_addr, "configured node addresses");
 
-    (dir, config, addr, testing_addr)
+    Ok((dir, config, addr, testing_addr))
 }
 
 /// Spawn a node with shared setup, config writing, and readiness wait.
@@ -122,27 +154,34 @@ pub async fn spawn_node<C>(
     config_filename: &str,
     binary_path: PathBuf,
     enable_logging: bool,
-) -> Result<NodeHandle<C>, tokio::time::error::Elapsed>
+) -> Result<NodeHandle<C>, SpawnNodeError>
 where
     C: NodeConfigCommon + Serialize,
 {
-    let (dir, config, addr, testing_addr) = prepare_node_config(config, log_prefix, enable_logging);
+    let (dir, config, addr, testing_addr) =
+        prepare_node_config(config, log_prefix, enable_logging)?;
     let config_path = dir.path().join(config_filename);
     super::lifecycle::spawn::write_config_with_injection(&config, &config_path, |yaml| {
         crate::nodes::common::config::injection::inject_ibd_into_cryptarchia(yaml)
     })
-    .expect("failed to write node config");
+    .map_err(|source| SpawnNodeError::WriteConfig {
+        path: config_path.clone(),
+        source,
+    })?;
 
     debug!(config_file = %config_path.display(), binary = %binary_path.display(), "spawning node process");
 
-    let child = Command::new(binary_path)
+    let child = Command::new(&binary_path)
         .arg(&config_path)
         .current_dir(dir.path())
         .stdin(Stdio::null())
         .stdout(Stdio::inherit())
         .stderr(Stdio::inherit())
         .spawn()
-        .expect("failed to spawn node process");
+        .map_err(|source| SpawnNodeError::Spawn {
+            binary: binary_path.clone(),
+            source,
+        })?;
 
     let mut handle = NodeHandle::new(child, dir, config, ApiClient::new(addr, testing_addr));
 
@@ -160,7 +199,7 @@ where
     if let Err(err) = ready {
         // Persist tempdir to aid debugging if readiness fails.
         let _ = persist_tempdir(&mut handle.tempdir, "nomos-node");
-        return Err(err);
+        return Err(SpawnNodeError::Readiness { source: err });
     }
 
     info!("node readiness confirmed via consensus_info");

testing-framework/core/src/nodes/executor.rs

@@ -17,7 +17,7 @@ use crate::{
         common::{
             binary::{BinaryConfig, BinaryResolver},
             lifecycle::{kill::kill_child, monitor::is_running},
-            node::{NodeAddresses, NodeConfigCommon, NodeHandle, spawn_node},
+            node::{NodeAddresses, NodeConfigCommon, NodeHandle, SpawnNodeError, spawn_node},
         },
     },
 };
@@ -60,7 +60,7 @@ impl Drop for Executor {
 }
 
 impl Executor {
-    pub async fn spawn(config: Config) -> Self {
+    pub async fn spawn(config: Config) -> Result<Self, SpawnNodeError> {
         let handle = spawn_node(
             config,
             LOGS_PREFIX,
@@ -68,12 +68,11 @@ impl Executor {
             binary_path(),
             !*IS_DEBUG_TRACING,
         )
-        .await
-        .expect("executor did not become ready");
+        .await?;
 
         info!("executor spawned and ready");
 
-        Self { handle }
+        Ok(Self { handle })
     }
 
     /// Check if the executor process is still running

testing-framework/core/src/nodes/validator.rs

@@ -3,7 +3,6 @@ use std::{ops::Deref, path::PathBuf, time::Duration};
 use nomos_node::Config;
 use nomos_tracing_service::LoggerLayer;
 pub use testing_framework_config::nodes::validator::create_validator_config;
-use tokio::time::error::Elapsed;
 use tracing::{debug, info};
 
 use super::{persist_tempdir, should_persist_tempdir};
@@ -14,7 +13,7 @@ use crate::{
         common::{
             binary::{BinaryConfig, BinaryResolver},
             lifecycle::{kill::kill_child, monitor::is_running},
-            node::{NodeAddresses, NodeConfigCommon, NodeHandle, spawn_node},
+            node::{NodeAddresses, NodeConfigCommon, NodeHandle, SpawnNodeError, spawn_node},
         },
     },
 };
@@ -73,7 +72,7 @@ impl Validator {
         self.handle.wait_for_exit(timeout).await
     }
 
-    pub async fn spawn(config: Config) -> Result<Self, Elapsed> {
+    pub async fn spawn(config: Config) -> Result<Self, SpawnNodeError> {
         let handle = spawn_node(
             config,
             LOGS_PREFIX,

testing-framework/core/src/topology/deployment.rs

@@ -1,9 +1,11 @@
 use std::collections::HashSet;
 
 use nomos_core::sdp::SessionNumber;
+use thiserror::Error;
 
 use crate::{
     nodes::{
+        common::node::SpawnNodeError,
         executor::{Executor, create_executor_config},
         validator::{Validator, create_validator_config},
     },
@@ -27,8 +29,14 @@ pub struct Topology {
 
 pub type DeployedNodes = (Vec<Validator>, Vec<Executor>);
 
+#[derive(Debug, Error)]
+pub enum SpawnTopologyError {
+    #[error(transparent)]
+    Node(#[from] SpawnNodeError),
+}
+
 impl Topology {
-    pub async fn spawn(config: TopologyConfig) -> Self {
+    pub async fn spawn(config: TopologyConfig) -> Result<Self, SpawnTopologyError> {
         let generated = TopologyBuilder::new(config.clone()).build();
         let n_validators = config.n_validators;
         let n_executors = config.n_executors;
@@ -38,12 +46,12 @@ impl Topology {
             .collect::<Vec<_>>();
 
         let (validators, executors) =
-            Self::spawn_validators_executors(node_configs, n_validators, n_executors).await;
+            Self::spawn_validators_executors(node_configs, n_validators, n_executors).await?;
 
-        Self {
+        Ok(Self {
             validators,
             executors,
-        }
+        })
     }
 
     pub async fn spawn_with_empty_membership(
@@ -51,7 +59,7 @@ impl Topology {
         ids: &[[u8; 32]],
         da_ports: &[u16],
         blend_ports: &[u16],
-    ) -> Self {
+    ) -> Result<Self, SpawnTopologyError> {
         let generated = TopologyBuilder::new(config.clone())
             .with_ids(ids.to_vec())
             .with_da_ports(da_ports.to_vec())
@@ -65,32 +73,32 @@ impl Topology {
 
         let (validators, executors) =
             Self::spawn_validators_executors(node_configs, config.n_validators, config.n_executors)
-                .await;
+                .await?;
 
-        Self {
+        Ok(Self {
             validators,
             executors,
-        }
+        })
     }
 
     pub(crate) async fn spawn_validators_executors(
         config: Vec<GeneralConfig>,
         n_validators: usize,
         n_executors: usize,
-    ) -> DeployedNodes {
+    ) -> Result<DeployedNodes, SpawnTopologyError> {
         let mut validators = Vec::new();
         for i in 0..n_validators {
             let config = create_validator_config(config[i].clone());
-            validators.push(Validator::spawn(config).await.unwrap());
+            validators.push(Validator::spawn(config).await?);
         }
 
         let mut executors = Vec::new();
         for i in 0..n_executors {
             let config = create_executor_config(config[n_validators + i].clone());
-            executors.push(Executor::spawn(config).await);
+            executors.push(Executor::spawn(config).await?);
         }
 
-        (validators, executors)
+        Ok((validators, executors))
     }
 
     #[must_use]

testing-framework/core/src/topology/generation.rs

@@ -5,7 +5,7 @@ use reqwest::{Client, Url};
 use crate::topology::{
     config::TopologyConfig,
     configs::{GeneralConfig, wallet::WalletAccount},
-    deployment::Topology,
+    deployment::{SpawnTopologyError, Topology},
     readiness::{HttpMembershipReadiness, HttpNetworkReadiness, ReadinessCheck, ReadinessError},
 };
 
@@ -103,7 +103,7 @@ impl GeneratedTopology {
         &self.config.wallet_config.accounts
     }
 
-    pub async fn spawn_local(&self) -> Topology {
+    pub async fn spawn_local(&self) -> Result<Topology, SpawnTopologyError> {
         let configs = self
             .nodes()
             .map(|node| node.general.clone())
@@ -114,12 +114,12 @@ impl GeneratedTopology {
             self.config.n_validators,
             self.config.n_executors,
         )
-        .await;
+        .await?;
 
-        Topology {
+        Ok(Topology {
             validators,
             executors,
-        }
+        })
     }
 
     pub async fn wait_remote_readiness(

testing-framework/deployers/local/src/runner.rs

@@ -4,7 +4,10 @@ use testing_framework_core::{
         BlockFeed, BlockFeedTask, Deployer, DynError, Metrics, NodeClients, RunContext, Runner,
         Scenario, ScenarioError, spawn_block_feed,
     },
-    topology::{deployment::Topology, readiness::ReadinessError},
+    topology::{
+        deployment::{SpawnTopologyError, Topology},
+        readiness::ReadinessError,
+    },
 };
 use thiserror::Error;
 use tracing::{debug, info};
@@ -19,6 +22,11 @@ pub struct LocalDeployer {
 /// Errors surfaced by the local deployer while driving a scenario.
 #[derive(Debug, Error)]
 pub enum LocalDeployerError {
+    #[error("failed to spawn local topology: {source}")]
+    Spawn {
+        #[source]
+        source: SpawnTopologyError,
+    },
     #[error("readiness probe failed: {source}")]
     ReadinessFailed {
         #[source]
@@ -101,7 +109,11 @@ impl LocalDeployer {
             executors = descriptors.executors().len(),
             "spawning local validators/executors"
         );
-        let topology = descriptors.clone().spawn_local().await;
+        let topology = descriptors
+            .clone()
+            .spawn_local()
+            .await
+            .map_err(|source| LocalDeployerError::Spawn { source })?;
 
         let skip_membership = !membership_check;
         wait_for_readiness(&topology, skip_membership)