Serve from other IPs (#142)

src/lune/builtins/net/config.rs

@@ -140,9 +140,11 @@ impl FromLua<'_> for RequestConfig {
 
 // Net serve config
 
+#[derive(Debug)]
 pub struct ServeConfig<'a> {
     pub handle_request: LuaFunction<'a>,
     pub handle_web_socket: Option<LuaFunction<'a>>,
+    pub address: Option<LuaString<'a>>,
 }
 
 impl<'lua> FromLua<'lua> for ServeConfig<'lua> {
@@ -152,11 +154,13 @@ impl<'lua> FromLua<'lua> for ServeConfig<'lua> {
                 return Ok(ServeConfig {
                     handle_request: f.clone(),
                     handle_web_socket: None,
+                    address: None,
                 })
             }
             LuaValue::Table(t) => {
                 let handle_request: Option<LuaFunction> = t.raw_get("handleRequest")?;
                 let handle_web_socket: Option<LuaFunction> = t.raw_get("handleWebSocket")?;
+                let address: Option<LuaString> = t.raw_get("address")?;
                 if handle_request.is_some() || handle_web_socket.is_some() {
                     return Ok(ServeConfig {
                         handle_request: handle_request.unwrap_or_else(|| {
@@ -174,6 +178,7 @@ impl<'lua> FromLua<'lua> for ServeConfig<'lua> {
                                 .expect("Failed to create default http responder function")
                         }),
                         handle_web_socket,
+                        address,
                     });
                 } else {
                     Some("Missing handleRequest and / or handleWebSocket".to_string())

src/lune/builtins/net/mod.rs

@@ -1,10 +1,15 @@
+use std::net::Ipv4Addr;
+
 use mlua::prelude::*;
 
 use hyper::header::CONTENT_ENCODING;
 
 use crate::lune::{scheduler::Scheduler, util::TableBuilder};
 
-use self::{server::create_server, util::header_map_to_table};
+use self::{
+    server::{bind_to_addr, create_server},
+    util::header_map_to_table,
+};
 
 use super::serde::{
     compress_decompress::{decompress, CompressDecompressFormat},
@@ -21,9 +26,10 @@ mod websocket;
 
 use client::{NetClient, NetClientBuilder};
 use config::{RequestConfig, ServeConfig};
-use server::bind_to_localhost;
 use websocket::NetWebSocket;
 
+const DEFAULT_IP_ADDRESS: Ipv4Addr = Ipv4Addr::new(127, 0, 0, 1);
+
 pub fn create(lua: &'static Lua) -> LuaResult<LuaTable> {
     NetClientBuilder::new()
         .headers(&[("User-Agent", create_user_agent_header())])?
@@ -137,7 +143,22 @@ where
         .app_data_ref::<&Scheduler>()
         .expect("Lua struct is missing scheduler");
 
-    let builder = bind_to_localhost(port)?;
+    let address: Ipv4Addr = match &config.address {
+        Some(addr) => {
+            let addr_str = addr.to_str()?;
+
+            addr_str
+                .trim_start_matches("http://")
+                .trim_start_matches("https://")
+                .parse()
+                .map_err(|_e| LuaError::RuntimeError(format!(
+                    "IP address format is incorrect (expected an IP in the form 'http://0.0.0.0' or '0.0.0.0', got '{addr_str}')"
+                )))?
+        }
+        None => DEFAULT_IP_ADDRESS,
+    };
+
+    let builder = bind_to_addr(address, port)?;
 
     create_server(lua, &sched, config, builder)
 }

src/lune/builtins/net/server.rs

@@ -1,4 +1,9 @@
-use std::{collections::HashMap, convert::Infallible, net::SocketAddr, sync::Arc};
+use std::{
+    collections::HashMap,
+    convert::Infallible,
+    net::{Ipv4Addr, SocketAddr},
+    sync::Arc,
+};
 
 use hyper::{
     server::{conn::AddrIncoming, Builder},
@@ -20,12 +25,13 @@ use super::{
     websocket::NetWebSocket,
 };
 
-pub(super) fn bind_to_localhost(port: u16) -> LuaResult<Builder<AddrIncoming>> {
-    let addr = SocketAddr::from(([127, 0, 0, 1], port));
+pub(super) fn bind_to_addr(address: Ipv4Addr, port: u16) -> LuaResult<Builder<AddrIncoming>> {
+    let addr = SocketAddr::from((address, port));
+
     match Server::try_bind(&addr) {
         Ok(b) => Ok(b),
         Err(e) => Err(LuaError::external(format!(
-            "Failed to bind to localhost on port {port}\n{}",
+            "Failed to bind to {addr}\n{}",
             e.to_string()
                 .replace("error creating server listener: ", "> ")
         ))),

tests/net/serve/requests.luau

@@ -5,8 +5,13 @@ local task = require("@lune/task")
 
 local PORT = 8080
 local URL = `http://127.0.0.1:{PORT}`
+local URL_EXTERNAL = `http://0.0.0.0`
 local RESPONSE = "Hello, lune!"
 
+-- A server should never be running before testing
+local isRunning = pcall(net.request, URL)
+assert(not isRunning, `a server is already running at {URL}`)
+
 -- Serve should not block the thread from continuing
 
 local thread = task.delay(1, function()
@@ -77,3 +82,32 @@ assert(
 		or string.find(message, "shut down"),
 	"The error message for calling stop twice on the net serve handle should be descriptive"
 )
+
+-- Serve should be able to bind to other IP addresses
+local handle2 = net.serve(PORT, {
+	address = URL_EXTERNAL,
+	handleRequest = function(request)
+		return `Response from {URL_EXTERNAL}:{PORT}`
+	end,
+})
+
+-- And any requests to that IP should succeed
+local response3 = net.request(`{URL_EXTERNAL}:{PORT}`).body
+assert(response3 ~= nil, "Invalid response from server")
+
+handle2.stop()
+
+-- Attempting to serve with a malformed IP address should throw an error
+local success3 = pcall(function()
+	net.serve(8080, {
+		address = "a.b.c.d",
+		handleRequest = function()
+			return RESPONSE
+		end,
+	})
+end)
+
+assert(not success3, "Server was created with malformed address")
+
+-- We have to manually exit so Windows CI doesn't get stuck forever
+process.exit(0)