dep: rm confy as a dep (#10290)

Co-authored-by: Alexey Shekhirin <a.shekhirin@gmail.com>

crates/node/builder/Cargo.toml

@@ -76,7 +76,6 @@ secp256k1 = { workspace = true, features = [
 aquamarine.workspace = true
 eyre.workspace = true
 fdlimit.workspace = true
-confy.workspace = true
 rayon.workspace = true
 
 # tracing

crates/node/builder/src/launch/common.rs

@@ -117,7 +117,7 @@ impl LaunchContext {
     pub fn load_toml_config(&self, config: &NodeConfig) -> eyre::Result<reth_config::Config> {
         let config_path = config.config.clone().unwrap_or_else(|| self.data_dir.config());
 
-        let mut toml_config = confy::load_path::<reth_config::Config>(&config_path)
+        let mut toml_config = reth_config::Config::from_path(&config_path)
             .wrap_err_with(|| format!("Could not load config file {config_path:?}"))?;
 
         Self::save_pruning_config_if_full_node(&mut toml_config, config, &config_path)?;
@@ -970,12 +970,8 @@ mod tests {
             )
             .unwrap();
 
-            assert_eq!(
-                reth_config.prune.as_ref().map(|p| p.block_interval),
-                node_config.prune_config().map(|p| p.block_interval)
-            );
+            let loaded_config = Config::from_path(config_path).unwrap();
 
-            let loaded_config: Config = confy::load_path(config_path).unwrap();
             assert_eq!(reth_config, loaded_config);
         })
     }

crates/node/core/Cargo.toml

@@ -51,6 +51,8 @@ humantime.workspace = true
 const_format.workspace = true
 rand.workspace = true
 derive_more.workspace = true
+toml.workspace = true
+serde.workspace = true
 
 # io
 dirs-next = "2.0.0"
@@ -77,6 +79,7 @@ futures.workspace = true
 # test vectors generation
 proptest.workspace = true
 tokio.workspace = true
+tempfile.workspace = true
 
 [features]
 optimism = [

crates/node/core/src/node_config.rs

@@ -8,10 +8,13 @@ use crate::{
     dirs::{ChainPath, DataDirPath},
     utils::get_single_header,
 };
+use eyre::eyre;
 use reth_chainspec::{ChainSpec, MAINNET};
 use reth_config::config::PruneConfig;
 use reth_db_api::database::Database;
 use reth_network_p2p::headers::client::HeadersClient;
+use serde::{de::DeserializeOwned, Serialize};
+use std::{fs, path::Path};
 
 use reth_primitives::{
     revm_primitives::EnvKzgSettings, BlockHashOrNumber, BlockNumber, Head, SealedHeader, B256,
@@ -365,6 +368,33 @@ impl NodeConfig {
     pub fn datadir(&self) -> ChainPath<DataDirPath> {
         self.datadir.clone().resolve_datadir(self.chain.chain)
     }
+
+    /// Load an application configuration from a specified path.
+    ///
+    /// A new configuration file is created with default values if none
+    /// exists.
+    pub fn load_path<T: Serialize + DeserializeOwned + Default>(
+        path: impl AsRef<Path>,
+    ) -> eyre::Result<T> {
+        let path = path.as_ref();
+        match fs::read_to_string(path) {
+            Ok(cfg_string) => {
+                toml::from_str(&cfg_string).map_err(|e| eyre!("Failed to parse TOML: {e}"))
+            }
+            Err(e) if e.kind() == std::io::ErrorKind::NotFound => {
+                if let Some(parent) = path.parent() {
+                    fs::create_dir_all(parent)
+                        .map_err(|e| eyre!("Failed to create directory: {e}"))?;
+                }
+                let cfg = T::default();
+                let s = toml::to_string_pretty(&cfg)
+                    .map_err(|e| eyre!("Failed to serialize to TOML: {e}"))?;
+                fs::write(path, s).map_err(|e| eyre!("Failed to write configuration file: {e}"))?;
+                Ok(cfg)
+            }
+            Err(e) => Err(eyre!("Failed to load configuration: {e}")),
+        }
+    }
 }
 
 impl Default for NodeConfig {