Feat. : Enable Dual Stack binding with ipv4 fallback for Vertd

Cargo.toml

@@ -24,6 +24,7 @@ rand = "0.9.0"
 rbtag = "0.3.0"
 serde = { version = "1.0.217", features = ["derive"] }
 serde_json = "1.0.138"
+socket2 = "0.5"
 strum = "0.27.1"
 strum_macros = "0.27.1"
 thiserror = "2.0.11"

src/http/mod.rs

@@ -1,13 +1,42 @@
+use std::net::{Ipv4Addr, Ipv6Addr, SocketAddr, TcpListener};
+
 use actix_cors::Cors;
 use actix_web::{web, App, HttpServer};
-use log::info;
+use log::{info, warn};
 use services::{download::download, upload::upload, version::version, websocket::websocket};
+use socket2::{Domain, Protocol, Socket, Type};
 
 use crate::http::services::keep::keep;
 
 mod response;
 mod services;
 
+/// Binds a dual-stack listener on `[::]:port` that accepts both IPv6 and IPv4
+/// (via IPv4-mapped addresses). If IPv6 is unavailable (e.g. disabled in the
+/// container), falls back to an IPv4-only listener on `0.0.0.0:port`.
+fn bind_dual_stack(port: u16) -> std::io::Result<TcpListener> {
+    let v6 = (|| -> std::io::Result<Socket> {
+        let socket = Socket::new(Domain::IPV6, Type::STREAM, Some(Protocol::TCP))?;
+        // Explicitly accept IPv4 too; the OS default differs (e.g. Windows/BSD).
+        socket.set_only_v6(false)?;
+        #[cfg(unix)]
+        socket.set_reuse_address(true)?;
+        socket.bind(&SocketAddr::from((Ipv6Addr::UNSPECIFIED, port)).into())?;
+        socket.listen(1024)?;
+        Ok(socket)
+    })();
+
+    let listener = match v6 {
+        Ok(socket) => TcpListener::from(socket),
+        Err(e) => {
+            warn!("IPv6 dual-stack bind failed ({e}); falling back to 0.0.0.0:{port}");
+            TcpListener::bind((Ipv4Addr::UNSPECIFIED, port))?
+        }
+    };
+    listener.set_nonblocking(true)?;
+    Ok(listener)
+}
+
 pub async fn start_http() -> anyhow::Result<()> {
     let server = HttpServer::new(|| {
         App::new()
@@ -27,11 +56,11 @@ pub async fn start_http() -> anyhow::Result<()> {
             )
     });
     let port = std::env::var("PORT").unwrap_or_else(|_| "24153".to_string());
-    if !port.chars().all(char::is_numeric) {
-        anyhow::bail!("PORT must be a number");
-    }
-    let ip = format!("0.0.0.0:{}", port);
-    info!("http server listening on {}", ip);
-    server.bind(ip)?.run().await?;
+    let port: u16 = port
+        .parse()
+        .map_err(|_| anyhow::anyhow!("PORT must be a number between 0 and 65535"))?;
+    let listener = bind_dual_stack(port)?;
+    info!("http server listening on {}", listener.local_addr()?);
+    server.listen(listener)?.run().await?;
     Ok(())
 }