change server bind address (rojo-rbx#403)

* web/mod.rs - change server bind address

127.0.0.1 is a loopback interface, and only works on the same host
0.0.0.0 will allow connections from other hosts

ideally, this should be a console arg - but it's a quick fix

* implement --address option, revert default bind address to 127.0.0.1

* revert silly autoformatting

* ok, actually using rustfmt now

* More precise --address flag description

* Use SocketAddr where available, take advantage of const-ness

* Display 'localhost' if address is loopback

* Update Changelog

Co-authored-by: Lucien Greathouse <me@lpghatguy.com>

CHANGELOG.md

@@ -1,6 +1,9 @@
 # Rojo Changelog
 
 ## Unreleased Changes
+* Added `--address` flag to `rojo serve` to allow for external connections. ([#403][pr-403])
+
+[pr-403]: https://github.com/rojo-rbx/rojo/pull/403
 
 ## [7.0.0-alpha.2][7.0.0-alpha.2] (February 19, 2021)
 * Fixed incorrect protocol version between the client and server.

src/cli/mod.rs

@@ -12,6 +12,7 @@ use std::{
     env,
     error::Error,
     fmt,
+    net::IpAddr,
     path::{Path, PathBuf},
     str::FromStr,
 };
@@ -186,7 +187,11 @@ pub struct ServeCommand {
     #[structopt(default_value = "")]
     pub project: PathBuf,
 
-    /// The port to listen on. Defaults to the project's preference, or 34872 if
+    /// The IP address to listen on. Defaults to `127.0.0.1`.
+    #[structopt(long)]
+    pub address: Option<IpAddr>,
+
+    /// The port to listen on. Defaults to the project's preference, or `34872` if
     /// it has none.
     #[structopt(long)]
     pub port: Option<u16>,

src/cli/serve.rs

@@ -1,5 +1,7 @@
 use std::{
     io::{self, Write},
+    net::IpAddr,
+    net::Ipv4Addr,
     sync::Arc,
 };
 
@@ -13,35 +15,43 @@ use crate::{
     web::LiveServer,
 };
 
+const DEFAULT_BIND_ADDRESS: Ipv4Addr = Ipv4Addr::new(127, 0, 0, 1);
 const DEFAULT_PORT: u16 = 34872;
 
 pub fn serve(global: GlobalOptions, options: ServeCommand) -> Result<()> {
     let vfs = Vfs::new_default();
 
     let session = Arc::new(ServeSession::new(vfs, &options.absolute_project())?);
 
+    let ip = options.address.unwrap_or(DEFAULT_BIND_ADDRESS.into());
+
     let port = options
         .port
         .or_else(|| session.project_port())
         .unwrap_or(DEFAULT_PORT);
 
     let server = LiveServer::new(session);
 
-    let _ = show_start_message(port, global.color.into());
-    server.start(port);
+    let _ = show_start_message(ip, port, global.color.into());
+    server.start((ip, port).into());
 
     Ok(())
 }
 
-fn show_start_message(port: u16, color: ColorChoice) -> io::Result<()> {
+fn show_start_message(bind_address: IpAddr, port: u16, color: ColorChoice) -> io::Result<()> {
     let writer = BufferWriter::stdout(color);
     let mut buffer = writer.buffer();
 
     writeln!(&mut buffer, "Rojo server listening:")?;
 
     write!(&mut buffer, "  Address: ")?;
     buffer.set_color(ColorSpec::new().set_fg(Some(Color::Green)).set_bold(true))?;
-    writeln!(&mut buffer, "localhost")?;
+
+    if bind_address.is_loopback() {
+        writeln!(&mut buffer, "localhost")?;
+    } else {
+        writeln!(&mut buffer, "{}", bind_address)?;
+    }
 
     buffer.set_color(&ColorSpec::new())?;
     write!(&mut buffer, "  Port:    ")?;

src/web/mod.rs

@@ -4,7 +4,7 @@ pub mod interface;
 mod ui;
 mod util;
 
-use std::sync::Arc;
+use std::{net::SocketAddr, sync::Arc};
 
 use futures::{
     future::{self, FutureResult},
@@ -57,9 +57,7 @@ impl LiveServer {
         LiveServer { serve_session }
     }
 
-    pub fn start(self, port: u16) {
-        let address = ([127, 0, 0, 1], port).into();
-
+    pub fn start(self, address: SocketAddr) {
         let server = Server::bind(&address)
             .serve(move || {
                 let service: FutureResult<_, hyper::Error> =