fix: correctly load config from env vars (#3)

Author: ayazabbas

Cargo.lock

@@ -1,6 +1,6 @@
 [package]
 name = "pyth-stream"
-version = "0.1.1"
+version = "0.1.2"
 edition = "2021"
 
 [lib]

Cargo.toml

@@ -1,4 +1,4 @@
-use anyhow::Result;
+use anyhow::{Context, Result};
 use async_nats::jetstream::{self};
 use async_nats::HeaderMap;
 use clap::Parser;
@@ -212,33 +212,30 @@ async fn fetch_price_updates(jetstream: jetstream::Context, config: &AppConfig)
 }
 
 fn load_config(args: &Args) -> Result<AppConfig> {
-    let mut config = Config::builder();
+    let mut builder = Config::builder();
     if let Some(config_path) = args.config.as_ref() {
         info!("Loading configuration from file: {:?}", config_path);
-        config = config.add_source(config::File::from(config_path.clone()));
+        builder = builder.add_source(config::File::from(config_path.clone()));
     } else {
         info!("No config file specified, using default 'config.toml'");
-        config = config.add_source(config::File::with_name("config.toml").required(false));
+        builder = builder.add_source(config::File::with_name("config.toml").required(false));
     }
 
     // Add environment variables
     info!("Adding environment variables to configuration");
-    config = config.add_source(config::Environment::with_prefix("PYTH"));
+    builder = builder.add_source(config::Environment::with_prefix("PYTH").separator("__"));
 
     // Build the configuration
     info!("Building configuration");
-    let config: AppConfig = match config.build()?.try_deserialize() {
-        Ok(cfg) => {
-            debug!("Configuration loaded successfully: {:?}", cfg);
-            cfg
-        }
-        Err(e) => {
-            error!("Failed to deserialize configuration: {}", e);
-            return Err(anyhow::anyhow!("Configuration error: {}", e));
-        }
-    };
+    let config = builder.build()?;
+
+    debug!("Raw config: {:?}", config);
+    let app_config: AppConfig = config
+        .try_deserialize()
+        .context("Failed to deserialize configuration")?;
 
-    Ok(config)
+    debug!("Parsed config: {:?}", app_config);
+    Ok(app_config)
 }
 
 #[tokio::main]

src/bin/pyth_reader.rs

@@ -102,14 +102,21 @@ async fn main() -> Result<()> {
 }
 
 fn load_config(args: &Args) -> Result<AppConfig> {
-    let mut config = Config::builder();
+    let mut builder = Config::builder();
     if let Some(config_path) = &args.config {
-        config = config.add_source(config::File::from(config_path.clone()));
+        builder = builder.add_source(config::File::from(config_path.clone()));
     } else {
-        config = config.add_source(config::File::with_name("config.toml").required(false));
+        builder = builder.add_source(config::File::with_name("config.toml").required(false));
     }
-    config = config.add_source(config::Environment::with_prefix("PYTH"));
-    Ok(config.build()?.try_deserialize()?)
+    builder = builder.add_source(config::Environment::with_prefix("PYTH").separator("__"));
+
+    let config = builder.build()?;
+    let app_config: AppConfig = config
+        .try_deserialize()
+        .context("Failed to deserialize config")?;
+
+    debug!("Parsed config: {:?}", app_config);
+    Ok(app_config)
 }
 
 async fn handle_connection(stream: TcpStream, clients: Clients) -> Result<()> {