Improve CLI

src/main.rs

@@ -1,14 +1,40 @@
+use clap::Parser;
 use log::info;
-
+use std::net::{IpAddr, TcpListener};
 mod options;
 mod server;
 
 mod elastic_query;
 mod elastic_response;
 
+#[derive(Parser, Debug)]
+struct Args {
+    #[clap(short, long, default_value = "::1")]
+    bind_address: IpAddr,
+
+    #[clap(short, long, default_value_t = 9876)]
+    port: u16,
+}
+
 fn main() {
     env_logger::init();
 
+    let args = Args::parse();
+
     info!("Starting server...");
-    rouille::start_server("0.0.0.0:80", move |request| server::serve_request(request));
+
+    let next_free_port = find_available_port(args.bind_address, args.port);
+
+    rouille::start_server((args.bind_address, next_free_port), move |request| {
+        server::serve_request(request)
+    });
+}
+
+fn find_available_port(address: IpAddr, from: u16) -> u16 {
+    (from..u16::MAX)
+        .find(|port| match TcpListener::bind((address, *port)) {
+            Ok(_) => true,
+            Err(_) => false,
+        })
+        .unwrap_or_else(|| panic!("Could not find any available port starting from {}!", from))
 }