WIP: better HTTP listeners

Cargo.lock

@@ -2269,6 +2269,17 @@ version = "0.0.46"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d4d2456c373231a208ad294c33dc5bff30051eafd954cd4caae83a712b12854d"
 
+[[package]]
+name = "listenfd"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "14e4fcc00ff6731d94b70e16e71f43bda62883461f31230742e3bc6dddf12988"
+dependencies = [
+ "libc",
+ "uuid",
+ "winapi",
+]
+
 [[package]]
 name = "lock_api"
 version = "0.4.9"
@@ -2350,6 +2361,7 @@ dependencies = [
  "futures-util",
  "hyper",
  "indoc",
+ "listenfd",
  "mas-config",
  "mas-email",
  "mas-handlers",
@@ -2390,6 +2402,7 @@ dependencies = [
  "figment",
  "indoc",
  "lettre",
+ "listenfd",
  "mas-email",
  "mas-iana",
  "mas-jose",
@@ -5182,6 +5195,12 @@ version = "2.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e8db7427f936968176eaa7cdf81b7f98b980b18495ec28f1b5791ac3bfe3eea9"
 
+[[package]]
+name = "uuid"
+version = "1.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dd6469f4314d5f1ffec476e05f17cc9a78bc7a27a6a857842170bdf8d6f98d2f"
+
 [[package]]
 name = "valuable"
 version = "0.1.0"

crates/cli/Cargo.toml

@@ -19,6 +19,7 @@ url = "2.3.1"
 argon2 = { version = "0.4.1", features = ["password-hash"] }
 watchman_client = "0.8.0"
 atty = "0.2.14"
+listenfd = "1.0.0"
 
 tracing = "0.1.36"
 tracing-appender = "0.2.2"

crates/cli/src/commands/server.rs

@@ -12,15 +12,14 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-use std::{
-    net::{SocketAddr, TcpListener},
-    sync::Arc,
-    time::Duration,
-};
+use std::{net::SocketAddr, sync::Arc, time::Duration};
 
 use anyhow::Context;
 use clap::Parser;
-use futures_util::stream::{StreamExt, TryStreamExt};
+use futures_util::{
+    future::FutureExt,
+    stream::{StreamExt, TryStreamExt},
+};
 use hyper::Server;
 use mas_config::RootConfig;
 use mas_email::Mailer;
@@ -138,16 +137,10 @@ async fn watch_templates(
 }
 
 impl Options {
+    #[allow(clippy::too_many_lines)]
     pub async fn run(&self, root: &super::Options) -> anyhow::Result<()> {
         let config: RootConfig = root.load_config()?;
 
-        let addr: SocketAddr = config
-            .http
-            .address
-            .parse()
-            .context("could not parse listener address")?;
-        let listener = TcpListener::bind(addr).context("could not bind address")?;
-
         // Connect to the mail server
         let mail_transport = config.email.transport.to_transport().await?;
         mail_transport.test_connection().await?;
@@ -223,6 +216,8 @@ impl Options {
 
         let homeserver = MatrixHomeserver::new(config.matrix.homeserver.clone());
 
+        let listeners_config = config.http.listeners.clone();
+
         // Explicitely the config to properly zeroize secret keys
         drop(config);
 
@@ -238,7 +233,7 @@ impl Options {
                 .context("could not watch for templates changes")?;
         }
 
-        let state = AppState {
+        let state = Arc::new(AppState {
             pool,
             templates,
             key_store,
@@ -247,18 +242,42 @@ impl Options {
             mailer,
             homeserver,
             policy_factory,
-        };
+        });
 
-        let router = mas_handlers::router(state)
-            .nest(mas_router::StaticAsset::route(), static_files)
+        let signal = shutdown_signal().shared();
+        let mut fd_manager = listenfd::ListenFd::from_env();
+
+        let futs = listeners_config
+            .into_iter()
+            .map(|listener_config| {
+                let signal = signal.clone();
+                let router = mas_handlers::router(state.clone())
+                    .nest(mas_router::StaticAsset::route(), static_files.clone())
                     .layer(ServerLayer::default());
 
-        info!("Listening on http://{}", listener.local_addr().unwrap());
+                let mut futs: Vec<_> = Vec::with_capacity(listener_config.binds.len());
+                for bind in listener_config.binds {
+                    let listener = bind.listener(&mut fd_manager)?;
+                    let router = router.clone();
 
-        Server::from_tcp(listener)?
+                    let addr = listener.local_addr()?;
+                    info!("Listening on http://{addr}");
+
+                    let fut = Server::from_tcp(listener)?
                         .serve(router.into_make_service_with_connect_info::<SocketAddr>())
-            .with_graceful_shutdown(shutdown_signal())
-            .await?;
+                        .with_graceful_shutdown(signal.clone());
+                    futs.push(fut);
+                }
+
+                anyhow::Ok(futures_util::future::try_join_all(futs))
+            })
+            .collect::<Result<Vec<_>, _>>()?;
+
+        futures_util::future::try_join_all(futs).await?;
+
+        // This ensures we're running, even if no listener are setup
+        // This is useful for only running the task runner
+        signal.await;
 
         Ok(())
     }

crates/config/Cargo.toml

@@ -24,6 +24,8 @@ serde_json = "1.0.85"
 sqlx = { version = "0.6.2", features = ["runtime-tokio-rustls", "postgres"] }
 lettre = { version = "0.10.1", default-features = false, features = ["serde", "builder"] }
 
+listenfd = "1.0.0"
+
 pem-rfc7468 = "0.6.0"
 rand = "0.8.5"
 

crates/config/src/sections/http.rs

@@ -12,9 +12,14 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-use std::path::PathBuf;
+use std::{
+    net::{SocketAddr, TcpListener},
+    path::PathBuf,
+};
 
+use anyhow::Context;
 use async_trait::async_trait;
+use listenfd::ListenFd;
 use schemars::JsonSchema;
 use serde::{Deserialize, Serialize};
 use url::Url;
@@ -42,18 +47,59 @@ fn http_address_example_4() -> &'static str {
     "0.0.0.0:8080"
 }
 
-/// Configuration related to the web server
-#[derive(Debug, Serialize, Deserialize, JsonSchema)]
-pub struct HttpConfig {
-    /// IP and port the server should listen to
+#[derive(Debug, Serialize, Deserialize, JsonSchema, Clone)]
+#[serde(untagged)]
+pub enum BindConfig {
+    Address {
         #[schemars(
             example = "http_address_example_1",
             example = "http_address_example_2",
             example = "http_address_example_3",
             example = "http_address_example_4"
         )]
-    #[serde(default = "default_http_address")]
-    pub address: String,
+        address: String,
+    },
+    FileDescriptor {
+        fd: usize,
+    },
+}
+
+impl BindConfig {
+    pub fn listener(self, fd_manager: &mut ListenFd) -> Result<TcpListener, anyhow::Error> {
+        match self {
+            BindConfig::Address { address } => {
+                let addr: SocketAddr = address
+                    .parse()
+                    .context("could not parse listener address")?;
+                let listener = TcpListener::bind(addr).context("could not bind address")?;
+                Ok(listener)
+            }
+
+            BindConfig::FileDescriptor { fd } => {
+                let listener = fd_manager
+                    .take_tcp_listener(fd)?
+                    .context("no listener found on file descriptor")?;
+                // XXX: Do I need that?
+                listener.set_nonblocking(true)?;
+                Ok(listener)
+            }
+        }
+    }
+}
+
+#[derive(Debug, Serialize, Deserialize, JsonSchema, Clone)]
+pub struct ListenerConfig {
+    pub name: Option<String>,
+
+    pub binds: Vec<BindConfig>,
+}
+
+/// Configuration related to the web server
+#[derive(Debug, Serialize, Deserialize, JsonSchema)]
+pub struct HttpConfig {
+    /// List of listeners to run
+    #[serde(default)]
+    pub listeners: Vec<ListenerConfig>,
 
     /// Path from which to serve static files. If not specified, it will serve
     /// the static files embedded in the server binary
@@ -67,8 +113,13 @@ pub struct HttpConfig {
 impl Default for HttpConfig {
     fn default() -> Self {
         Self {
-            address: default_http_address(),
             web_root: None,
+            listeners: vec![ListenerConfig {
+                name: None,
+                binds: vec![BindConfig::Address {
+                    address: default_http_address(),
+                }],
+            }],
             public_base: default_public_base(),
         }
     }

crates/handlers/src/lib.rs

@@ -252,7 +252,7 @@ where
 
 #[must_use]
 #[allow(clippy::trait_duplication_in_bounds)]
-pub fn router<S, B>(state: S) -> Router<S, B>
+pub fn router<S, B>(state: Arc<S>) -> Router<S, B>
 where
     B: HttpBody + Send + 'static,
     <B as HttpBody>::Data: Send,
@@ -267,8 +267,6 @@ where
     Mailer: FromRef<S>,
     MatrixHomeserver: FromRef<S>,
 {
-    let state = Arc::new(state);
-
     let api_router = api_router(state.clone());
     let compat_router = compat_router(state.clone());
     let human_router = human_router(state);