allow listening on multiple ports in config

This is a config compatibility break.

The ability to listen on multiple ports, including both TLS and non-TLS,
is necessary for running complement against grapevine.

nix/modules/default/default.nix

@@ -29,13 +29,6 @@ in
       type = types.submodule {
         freeformType = format.type;
         options = {
-          address = lib.mkOption {
-            type = types.nonEmptyStr;
-            description = ''
-              The local IP address to bind to.
-            '';
-            default = "::1";
-          };
           conduit_compat = lib.mkOption {
             type = types.bool;
             description = ''
@@ -56,12 +49,18 @@ in
               then "/var/lib/matrix-conduit"
               else "/var/lib/grapevine";
           };
-          port = lib.mkOption {
-            type = types.port;
+          listen = lib.mkOption {
+            type = types.listOf format.type;
             description = ''
-              The local port to bind to.
+              List of places to listen for incoming connections.
             '';
-            default = 6167;
+            default = [
+              {
+                type = "tcp";
+                address = "::1";
+                port = 6167;
+              }
+            ];
           };
         };
       };

src/config.rs

@@ -25,10 +25,8 @@ pub(crate) static DEFAULT_PATH: Lazy<PathBuf> =
 pub(crate) struct Config {
     #[serde(default = "false_fn")]
     pub(crate) conduit_compat: bool,
-    #[serde(default = "default_address")]
-    pub(crate) address: IpAddr,
-    #[serde(default = "default_port")]
-    pub(crate) port: u16,
+    #[serde(default = "default_listen")]
+    pub(crate) listen: Vec<ListenConfig>,
     pub(crate) tls: Option<TlsConfig>,
 
     pub(crate) server_name: OwnedServerName,
@@ -98,6 +96,19 @@ pub(crate) struct TlsConfig {
     pub(crate) key: String,
 }
 
+#[derive(Debug, Deserialize)]
+#[serde(tag = "type", rename_all = "snake_case")]
+pub(crate) enum ListenConfig {
+    Tcp {
+        #[serde(default = "default_address")]
+        address: IpAddr,
+        #[serde(default = "default_port")]
+        port: u16,
+        #[serde(default = "false_fn")]
+        tls: bool,
+    },
+}
+
 fn false_fn() -> bool {
     false
 }
@@ -106,6 +117,14 @@ fn true_fn() -> bool {
     true
 }
 
+fn default_listen() -> Vec<ListenConfig> {
+    vec![ListenConfig::Tcp {
+        address: default_address(),
+        port: default_port(),
+        tls: false,
+    }]
+}
+
 fn default_address() -> IpAddr {
     Ipv4Addr::LOCALHOST.into()
 }

src/error.rs

@@ -104,6 +104,15 @@ pub(crate) enum ConfigSearch {
 #[allow(missing_docs)]
 #[derive(Error, Debug)]
 pub(crate) enum Serve {
+    #[error("no listeners were specified in the configuration file")]
+    NoListeners,
+
+    #[error(
+        "listener requested TLS, but no TLS cert was specified in the \
+         configuration file. Please set 'tls.certs' and 'tls.key'"
+    )]
+    NoTlsCerts,
+
     #[error("failed to read TLS cert and key files at {certs:?} and {key:?}")]
     LoadCerts {
         certs: String,

src/main.rs

@@ -15,6 +15,7 @@ use axum::{
 use axum_server::{
     bind, bind_rustls, tls_rustls::RustlsConfig, Handle as ServerHandle,
 };
+use futures_util::FutureExt;
 use http::{
     header::{self, HeaderName},
     Method, StatusCode, Uri,
@@ -26,14 +27,14 @@ use ruma::api::{
     },
     IncomingRequest,
 };
-use tokio::signal;
+use tokio::{signal, task::JoinSet};
 use tower::ServiceBuilder;
 use tower_http::{
     cors::{self, CorsLayer},
     trace::TraceLayer,
     ServiceBuilderExt as _,
 };
-use tracing::{debug, info, info_span, warn, Instrument};
+use tracing::{debug, error, info, info_span, warn, Instrument};
 
 mod api;
 mod args;
@@ -46,7 +47,7 @@ mod utils;
 
 pub(crate) use api::ruma_wrapper::{Ar, Ra};
 use api::{client_server, server_server};
-pub(crate) use config::Config;
+pub(crate) use config::{Config, ListenConfig};
 pub(crate) use database::KeyValueDatabase;
 pub(crate) use service::{pdu::PduEvent, Services};
 #[cfg(all(not(target_env = "msvc"), feature = "jemalloc"))]
@@ -135,7 +136,6 @@ async fn run_server() -> Result<(), error::Serve> {
     use error::Serve as Error;
 
     let config = &services().globals.config;
-    let addr = SocketAddr::from((config.address, config.port));
 
     let x_requested_with = HeaderName::from_static("x-requested-with");
 
@@ -184,36 +184,60 @@ async fn run_server() -> Result<(), error::Serve> {
         .layer(axum::middleware::from_fn(observability::http_metrics_layer));
 
     let app = routes(config).layer(middlewares).into_make_service();
-    let handle = ServerHandle::new();
+    let mut handles = Vec::new();
+    let mut servers = JoinSet::new();
 
-    tokio::spawn(shutdown_signal(handle.clone()));
+    let tls_config = if let Some(tls) = &config.tls {
+        Some(RustlsConfig::from_pem_file(&tls.certs, &tls.key).await.map_err(
+            |err| Error::LoadCerts {
+                certs: tls.certs.clone(),
+                key: tls.key.clone(),
+                err,
+            },
+        )?)
+    } else {
+        None
+    };
 
-    match &config.tls {
-        Some(tls) => {
-            let conf = RustlsConfig::from_pem_file(&tls.certs, &tls.key)
-                .await
-                .map_err(|err| Error::LoadCerts {
-                    certs: tls.certs.clone(),
-                    key: tls.key.clone(),
-                    err,
-                })?;
-            let server = bind_rustls(addr, conf).handle(handle).serve(app);
+    if config.listen.is_empty() {
+        return Err(Error::NoListeners);
+    }
 
-            #[cfg(feature = "systemd")]
-            sd_notify::notify(true, &[sd_notify::NotifyState::Ready])
-                .expect("should be able to notify systemd");
-
-            server.await.map_err(Error::Listen)?;
+    for listen in &config.listen {
+        match listen {
+            ListenConfig::Tcp {
+                address,
+                port,
+                tls,
+            } => {
+                let addr = SocketAddr::from((*address, *port));
+                let handle = ServerHandle::new();
+                handles.push(handle.clone());
+                let server = if *tls {
+                    let tls_config =
+                        tls_config.clone().ok_or(Error::NoTlsCerts)?;
+                    bind_rustls(addr, tls_config)
+                        .handle(handle)
+                        .serve(app.clone())
+                        .left_future()
+                } else {
+                    bind(addr).handle(handle).serve(app.clone()).right_future()
+                };
+                servers.spawn(server);
+            }
         }
-        None => {
-            let server = bind(addr).handle(handle).serve(app);
+    }
 
-            #[cfg(feature = "systemd")]
-            sd_notify::notify(true, &[sd_notify::NotifyState::Ready])
-                .expect("should be able to notify systemd");
+    #[cfg(feature = "systemd")]
+    sd_notify::notify(true, &[sd_notify::NotifyState::Ready])
+        .expect("should be able to notify systemd");
 
-            server.await.map_err(Error::Listen)?;
-        }
+    tokio::spawn(shutdown_signal(handles));
+
+    while let Some(result) = servers.join_next().await {
+        result
+            .expect("should be able to join server task")
+            .map_err(Error::Listen)?;
     }
 
     Ok(())
@@ -456,7 +480,7 @@ fn routes(config: &Config) -> Router {
     }
 }
 
-async fn shutdown_signal(handle: ServerHandle) {
+async fn shutdown_signal(handles: Vec<ServerHandle>) {
     let ctrl_c = async {
         signal::ctrl_c().await.expect("failed to install Ctrl+C handler");
     };
@@ -480,10 +504,13 @@ async fn shutdown_signal(handle: ServerHandle) {
     }
 
     warn!("Received {}, shutting down...", sig);
-    handle.graceful_shutdown(Some(Duration::from_secs(30)));
 
     services().globals.shutdown();
 
+    for handle in handles {
+        handle.graceful_shutdown(Some(Duration::from_secs(30)));
+    }
+
     #[cfg(feature = "systemd")]
     sd_notify::notify(true, &[sd_notify::NotifyState::Stopping])
         .expect("should be able to notify systemd");