Add dotenv support with auto-load and --env-file flag

.env.example

@@ -0,0 +1,3 @@
+# PoCW Economics
+POCW_ENABLED=false
+POCW_TRANSFER_FEE=21000

.gitignore

@@ -15,6 +15,9 @@ Thumbs.db
 **/*.rs.bk
 Cargo.lock
 
+# Environment
+.env
+
 # Logs
 *.log
 logs/

README.md

@@ -168,13 +168,17 @@ cargo test --all
 #### 1. Start Validator
 
 ```bash
-# Set environment variables
+# Using an env file (auto-loads .env from working directory)
+./target/release/setu-validator
+
+# Or specify a custom env file
+./target/release/setu-validator --env-file config/prod.env
+
+# Or set environment variables directly
 export VALIDATOR_ID=validator-1
 export VALIDATOR_HTTP_PORT=8080
 export VALIDATOR_P2P_PORT=9000
 export VALIDATOR_DB_PATH=/tmp/setu/validator
-
-# Start validator
 ./target/release/setu-validator
 ```
 

setu-validator/README.md

@@ -50,7 +50,10 @@ Validator node for the Setu network. Responsible for verifying events, maintaini
 # Start validator with default config
 cargo run -p setu-validator
 
-# With environment variables
+# With an env file (auto-loads .env from working directory, or use --env-file)
+cargo run -p setu-validator -- --env-file .env
+
+# With inline environment variables
 VALIDATOR_ID=validator_1 \
 VALIDATOR_PORT=8001 \
 IS_LEADER=true \

setu-validator/src/main.rs

@@ -94,8 +94,51 @@ fn load_key_info(key_file: &str) -> anyhow::Result<(String, Vec<u8>, Vec<u8>)> {
     Ok((account_address, public_key, signature))
 }
 
+/// Load environment variables from a dotenv file.
+/// Priority: `--env-file <path>` flag, then `.env` in the working directory.
+/// Each line should be KEY=VALUE (comments and blank lines are skipped).
+fn load_env_file() {
+    let args: Vec<String> = std::env::args().collect();
+    let explicit = args.windows(2)
+        .find(|w| w[0] == "--env-file")
+        .map(|w| w[1].clone());
+
+    let path = match explicit {
+        Some(p) => p,
+        None => {
+            // Auto-load .env from working directory if it exists
+            if std::path::Path::new(".env").exists() {
+                ".env".to_string()
+            } else {
+                return;
+            }
+        }
+    };
+
+    let content = match std::fs::read_to_string(&path) {
+        Ok(c) => c,
+        Err(e) => {
+            eprintln!("Failed to read env file {}: {}", path, e);
+            std::process::exit(1);
+        }
+    };
+
+    for line in content.lines() {
+        let line = line.trim();
+        if line.is_empty() || line.starts_with('#') {
+            continue;
+        }
+        if let Some((key, value)) = line.split_once('=') {
+            std::env::set_var(key.trim(), value.trim());
+        }
+    }
+}
+
 #[tokio::main]
 async fn main() -> anyhow::Result<()> {
+    // Load .env automatically, or from --env-file <path>
+    load_env_file();
+
     // Initialize tracing with more detailed output
     tracing_subscriber::fmt()
         .with_max_level(Level::DEBUG)