Allow config path from FOURTH_CONFIG

src/main.rs

@@ -5,10 +5,13 @@ mod servers;
 use crate::config::Config;
 use crate::servers::Server;
 
+use std::env;
 use log::{debug, error};
 
 fn main() {
-    let config = match Config::new("/etc/fourth/config.yaml") {
+    let config_path = env::var("FOURTH_CONFIG").unwrap_or_else(|_| "/etc/fourth/config.yaml".to_string());
+
+    let config = match Config::new(&config_path) {
         Ok(config) => config,
         Err(e) => {
             println!("Could not load config: {:?}", e);