feat: DENO_SERVE_ADDRESS duplicate option (#29109)

if `duplicate` is passed in DENO_SERVE_ADDRESS, use its value to create
a second listener instead of overriding the options the user passed.

ext/http/00_serve.ts

@@ -40,6 +40,7 @@ const {
   PromisePrototypeCatch,
   SafeArrayIterator,
   SafePromisePrototypeFinally,
+  SafePromiseAll,
   PromisePrototypeThen,
   StringPrototypeIncludes,
   Symbol,
@@ -787,43 +788,88 @@ function serve(arg1, arg2) {
     options = { __proto__: null };
   }
 
-  const { 0: overrideKind, 1: overrideHost, 2: overridePort } =
+  const {
-    op_http_serve_address_override();
+    0: overrideKind,
-  switch (overrideKind) {
+    1: overrideHost,
-    case 1: {
+    2: overridePort,
-      // TCP
+    3: duplicateListener,
-      options = {
+  } = op_http_serve_address_override();
-        ...options,
+  if (overrideKind) {
-        hostname: overrideHost,
+    let envOptions = duplicateListener ? { __proto__: null } : options;
-        port: overridePort,
+
-      };
+    switch (overrideKind) {
-      delete options.path;
+      case 1: {
-      delete options.cid;
+        // TCP
-      break;
+        envOptions = {
+          ...envOptions,
+          hostname: overrideHost,
+          port: overridePort,
+        };
+        delete envOptions.path;
+        delete envOptions.cid;
+        break;
+      }
+      case 2: {
+        // Unix
+        envOptions = {
+          ...envOptions,
+          path: overrideHost,
+        };
+        delete envOptions.hostname;
+        delete envOptions.cid;
+        delete envOptions.port;
+        break;
+      }
+      case 3: {
+        // Vsock
+        envOptions = {
+          ...envOptions,
+          cid: Number(overrideHost),
+          port: overridePort,
+        };
+        delete envOptions.hostname;
+        delete envOptions.path;
+        break;
+      }
     }
-    case 2: {
+
-      // Unix
+    if (duplicateListener) {
-      options = {
+      envOptions.onListen = () => {
-        ...options,
+        // override default console.log behavior
-        path: overrideHost,
       };
-      delete options.hostname;
+      const envListener = serveInner(envOptions, handler);
-      delete options.port;
+      const userListener = serveInner(options, handler);
-      break;
+
-    }
+      return {
-    case 3: {
+        addr: userListener.addr,
-      // Vsock
+        finished: SafePromiseAll([envListener.finished, userListener.finished]),
-      options = {
+        shutdown() {
-        ...options,
+          return SafePromiseAll([
-        cid: Number(overrideHost),
+            envListener.shutdown(),
-        port: overridePort,
+            userListener.shutdown(),
+          ]);
+        },
+        ref() {
+          envListener.ref();
+          userListener.ref();
+        },
+        unref() {
+          envListener.unref();
+          userListener.unref();
+        },
+        [SymbolAsyncDispose]() {
+          return this.shutdown();
+        },
       };
-      delete options.hostname;
-      delete options.path;
-      break;
     }
+
+    options = envOptions;
   }
 
+  return serveInner(options, handler);
+}
+
+function serveInner(options, handler) {
   const wantsHttps = hasTlsKeyPairOptions(options);
   const wantsUnix = ObjectHasOwn(options, "path");
   const wantsVsock = ObjectHasOwn(options, "cid");
@@ -1071,41 +1117,52 @@ internals.serveHttpOnListener = serveHttpOnListener;
 internals.serveHttpOnConnection = serveHttpOnConnection;
 
 function registerDeclarativeServer(exports) {
-  if (ObjectHasOwn(exports, "fetch")) {
+  if (!ObjectHasOwn(exports, "fetch")) return;
-    if (typeof exports.fetch !== "function") {
-      throw new TypeError(
-        "Invalid type for fetch: must be a function with a single or no parameter",
-      );
-    }
-    return ({ servePort, serveHost, serveIsMain, serveWorkerCount }) => {
-      Deno.serve({
-        port: servePort,
-        hostname: serveHost,
-        [kLoadBalanced]: (serveIsMain && serveWorkerCount > 1) ||
-          serveWorkerCount !== null,
-        onListen: ({ port, hostname }) => {
-          if (serveIsMain) {
-            const nThreads = serveWorkerCount > 1
-              ? ` with ${serveWorkerCount} threads`
-              : "";
-            const host = formatHostName(hostname);
 
-            import.meta.log(
+  if (typeof exports.fetch !== "function") {
-              "info",
+    throw new TypeError("Invalid type for fetch: must be a function");
-              `%cdeno serve%c: Listening on %chttp://${host}:${port}/%c${nThreads}`,
-              "color: green",
-              "color: inherit",
-              "color: yellow",
-              "color: inherit",
-            );
-          }
-        },
-        handler: (req, connInfo) => {
-          return exports.fetch(req, connInfo);
-        },
-      });
-    };
   }
+
+  return ({ servePort, serveHost, serveIsMain, serveWorkerCount }) => {
+    Deno.serve({
+      port: servePort,
+      hostname: serveHost,
+      [kLoadBalanced]: (serveIsMain && serveWorkerCount > 1) ||
+        serveWorkerCount !== null,
+      onListen: ({ transport, port, hostname, path, cid }) => {
+        if (serveIsMain) {
+          const nThreads = serveWorkerCount > 1
+            ? ` with ${serveWorkerCount} threads`
+            : "";
+
+          let target;
+          switch (transport) {
+            case "tcp":
+              target = `http://${formatHostName(hostname)}:${port}/`;
+              break;
+            case "unix":
+              target = path;
+              break;
+            case "vsock":
+              target = `vsock:${cid}:${port}`;
+              break;
+          }
+
+          import.meta.log(
+            "info",
+            `%cdeno serve%c: Listening on %c${target}%c${nThreads}`,
+            "color: green",
+            "color: inherit",
+            "color: yellow",
+            "color: inherit",
+          );
+        }
+      },
+      handler: (req, connInfo) => {
+        return exports.fetch(req, connInfo);
+      },
+    });
+  };
 }
 
 export {

ext/http/lib.rs

@@ -1693,14 +1693,18 @@ fn extract_network_stream<U: CanDowncastUpgrade>(
 
 #[op2]
 #[serde]
-pub fn op_http_serve_address_override() -> (u8, String, u32) {
+pub fn op_http_serve_address_override() -> (u8, String, u32, bool) {
   match std::env::var("DENO_SERVE_ADDRESS") {
     Ok(val) => parse_serve_address(&val),
-    Err(_) => (0, String::new(), 0),
+    Err(_) => (0, String::new(), 0, false),
   }
 }
 
-fn parse_serve_address(input: &str) -> (u8, String, u32) {
+fn parse_serve_address(input: &str) -> (u8, String, u32, bool) {
+  let (input, duplicate) = match input.strip_prefix("duplicate,") {
+    Some(input) => (input, true),
+    None => (input, false),
+  };
   match input.split_once(':') {
     Some(("tcp", addr)) => {
       // TCP address
@@ -1710,11 +1714,11 @@ fn parse_serve_address(input: &str) -> (u8, String, u32) {
             SocketAddr::V4(v4) => v4.ip().to_string(),
             SocketAddr::V6(v6) => format!("[{}]", v6.ip()),
           };
-          (1, hostname, addr.port() as u32)
+          (1, hostname, addr.port() as u32, duplicate)
         }
         Err(_) => {
           log::error!("DENO_SERVE_ADDRESS: invalid TCP address: {}", addr);
-          (0, String::new(), 0)
+          (0, String::new(), 0, false)
         }
       }
     }
@@ -1722,9 +1726,9 @@ fn parse_serve_address(input: &str) -> (u8, String, u32) {
       // Unix socket path
       if addr.is_empty() {
         log::error!("DENO_SERVE_ADDRESS: empty unix socket path");
-        return (0, String::new(), 0);
+        return (0, String::new(), 0, duplicate);
       }
-      (2, addr.to_string(), 0)
+      (2, addr.to_string(), 0, duplicate)
     }
     Some(("vsock", addr)) => {
       // Vsock address
@@ -1737,7 +1741,7 @@ fn parse_serve_address(input: &str) -> (u8, String, u32) {
               Ok(cid) => cid.to_string(),
               Err(_) => {
                 log::error!("DENO_SERVE_ADDRESS: invalid vsock CID: {}", cid);
-                return (0, String::new(), 0);
+                return (0, String::new(), 0, false);
               }
             }
           };
@@ -1745,17 +1749,17 @@ fn parse_serve_address(input: &str) -> (u8, String, u32) {
             Ok(port) => port,
             Err(_) => {
               log::error!("DENO_SERVE_ADDRESS: invalid vsock port: {}", port);
-              return (0, String::new(), 0);
+              return (0, String::new(), 0, false);
             }
           };
-          (3, cid, port)
+          (3, cid, port, duplicate)
         }
-        None => (0, String::new(), 0),
+        None => (0, String::new(), 0, false),
       }
     }
     Some((_, _)) | None => {
       log::error!("DENO_SERVE_ADDRESS: invalid address format: {}", input);
-      (0, String::new(), 0)
+      (0, String::new(), 0, false)
     }
   }
 }
@@ -1768,31 +1772,43 @@ mod tests {
   fn test_parse_serve_address() {
     assert_eq!(
       parse_serve_address("tcp:127.0.0.1:8080"),
-      (1, "127.0.0.1".to_string(), 8080)
+      (1, "127.0.0.1".to_string(), 8080, false)
     );
     assert_eq!(
       parse_serve_address("tcp:[::1]:9000"),
-      (1, "[::1]".to_string(), 9000)
+      (1, "[::1]".to_string(), 9000, false)
+    );
+    assert_eq!(
+      parse_serve_address("duplicate,tcp:[::1]:9000"),
+      (1, "[::1]".to_string(), 9000, true)
     );
 
     assert_eq!(
       parse_serve_address("unix:/var/run/socket.sock"),
-      (2, "/var/run/socket.sock".to_string(), 0)
+      (2, "/var/run/socket.sock".to_string(), 0, false)
+    );
+    assert_eq!(
+      parse_serve_address("duplicate,unix:/var/run/socket.sock"),
+      (2, "/var/run/socket.sock".to_string(), 0, true)
     );
 
     assert_eq!(
       parse_serve_address("vsock:1234:5678"),
-      (3, "1234".to_string(), 5678)
+      (3, "1234".to_string(), 5678, false)
     );
     assert_eq!(
       parse_serve_address("vsock:-1:5678"),
-      (3, "-1".to_string(), 5678)
+      (3, "-1".to_string(), 5678, false)
+    );
+    assert_eq!(
+      parse_serve_address("duplicate,vsock:-1:5678"),
+      (3, "-1".to_string(), 5678, true)
     );
 
-    assert_eq!(parse_serve_address("tcp:"), (0, String::new(), 0));
+    assert_eq!(parse_serve_address("tcp:"), (0, String::new(), 0, false));
-    assert_eq!(parse_serve_address("unix:"), (0, String::new(), 0));
+    assert_eq!(parse_serve_address("unix:"), (0, String::new(), 0, false));
-    assert_eq!(parse_serve_address("vsock:"), (0, String::new(), 0));
+    assert_eq!(parse_serve_address("vsock:"), (0, String::new(), 0, false));
-    assert_eq!(parse_serve_address("foo:"), (0, String::new(), 0));
+    assert_eq!(parse_serve_address("foo:"), (0, String::new(), 0, false));
-    assert_eq!(parse_serve_address("bar"), (0, String::new(), 0));
+    assert_eq!(parse_serve_address("bar"), (0, String::new(), 0, false));
   }
 }

tests/integration/serve_tests.rs

@@ -340,3 +340,62 @@ async fn deno_run_serve_with_unix_socket_from_env() {
   child.kill().unwrap();
   child.wait().unwrap();
 }
+
+#[tokio::test]
+#[cfg(unix)]
+async fn deno_run_serve_with_duplicate_env_addr() {
+  use tokio::io::AsyncReadExt;
+  use tokio::io::AsyncWriteExt;
+  use tokio::net::UnixStream;
+
+  let dir = tempfile::TempDir::new().unwrap();
+  let sock = dir.path().join("listen.sock");
+  let mut child = util::deno_cmd()
+    .current_dir(util::testdata_path())
+    .arg("run")
+    .arg("--allow-net")
+    .arg(format!("--allow-read={}", sock.display()))
+    .arg(format!("--allow-write={}", sock.display()))
+    .arg("./serve/run_serve.ts")
+    .env(
+      "DENO_SERVE_ADDRESS",
+      format!("duplicate,unix:{}", sock.display()),
+    )
+    .stderr_piped()
+    .spawn()
+    .unwrap();
+  let stderr = BufReader::new(child.stderr.as_mut().unwrap());
+  let msg = stderr.lines().next().unwrap().unwrap();
+
+  let port_regex = Regex::new(r"https?:[^:]+:(\d+)").unwrap();
+  let port = port_regex.captures(&msg).unwrap().get(1).unwrap().as_str();
+
+  {
+    let client = reqwest::Client::builder().build().unwrap();
+
+    let res = client
+      .get(format!("http://127.0.0.1:{port}"))
+      .send()
+      .await
+      .unwrap();
+    assert_eq!(200, res.status());
+
+    let body = res.text().await.unwrap();
+    assert_eq!(body, "Deno.serve() works!");
+  }
+
+  {
+    // reqwest does not support connecting to unix sockets yet, so here we send the http
+    // payload directly
+    let mut conn = UnixStream::connect(dir.path().join("listen.sock"))
+      .await
+      .unwrap();
+    conn.write_all(b"GET / HTTP/1.0\r\n\r\n").await.unwrap();
+    let mut response = String::new();
+    conn.read_to_string(&mut response).await.unwrap();
+    assert!(response.ends_with("\r\nDeno.serve() works!"));
+  }
+
+  child.kill().unwrap();
+  child.wait().unwrap();
+}