feat(unstable): add unix domain socket support to Deno.serve (#20759)

7 files changed, 216 insertions, 15 deletions

diff --git a/cli/tests/unit/net_test.ts b/cli/tests/unit/net_test.ts
index 54edf31fc..2a98b5e26 100644
--- a/cli/tests/unit/net_test.ts
+++ b/cli/tests/unit/net_test.ts
@@ -9,8 +9,8 @@ import {
   delay,
   execCode,
   execCode2,
+  tmpUnixSocketPath,
 } from "./test_util.ts";
-import { join } from "../../../test_util/std/path/mod.ts";
 
 // Since these tests may run in parallel, ensure this port is unique to this file
 const listenPort = 4503;
@@ -49,11 +49,6 @@ Deno.test(
   },
 );
 
-function tmpUnixSocketPath(): string {
-  const folder = Deno.makeTempDirSync();
-  return join(folder, "socket");
-}
-
 Deno.test(
   {
     ignore: Deno.build.os === "windows",
diff --git a/cli/tests/unit/serve_test.ts b/cli/tests/unit/serve_test.ts
index 193b04ed1..6f58db006 100644
--- a/cli/tests/unit/serve_test.ts
+++ b/cli/tests/unit/serve_test.ts
@@ -15,6 +15,7 @@ import {
   deferred,
   execCode,
   fail,
+  tmpUnixSocketPath,
 } from "./test_util.ts";
 
 // Since these tests may run in parallel, ensure this port is unique to this file
@@ -3715,3 +3716,37 @@ async function curlRequestWithStdErr(args: string[]) {
   assert(success);
   return [new TextDecoder().decode(stdout), new TextDecoder().decode(stderr)];
 }
+
+Deno.test(
+  {
+    ignore: Deno.build.os === "windows",
+    permissions: { run: true, read: true, write: true },
+  },
+  async function httpServerUnixDomainSocket() {
+    const d = deferred();
+    const ac = new AbortController();
+    const filePath = tmpUnixSocketPath();
+    const server = Deno.serve(
+      {
+        signal: ac.signal,
+        path: filePath,
+        onListen(info) {
+          d.resolve(info);
+        },
+        onError: createOnErrorCb(ac),
+      },
+      (_req, { remoteAddr }) => {
+        assertEquals(remoteAddr, { path: filePath, transport: "unix" });
+        return new Response("hello world!");
+      },
+    );
+
+    assertEquals(await d, { path: filePath });
+    assertEquals(
+      "hello world!",
+      await curlRequest(["--unix-socket", filePath, "http://localhost"]),
+    );
+    ac.abort();
+    await server.finished;
+  },
+);
diff --git a/cli/tests/unit/test_util.ts b/cli/tests/unit/test_util.ts
index 23713faf4..de1e8e8c5 100644
--- a/cli/tests/unit/test_util.ts
+++ b/cli/tests/unit/test_util.ts
@@ -2,7 +2,7 @@
 
 import * as colors from "../../../test_util/std/fmt/colors.ts";
 export { colors };
-import { resolve } from "../../../test_util/std/path/mod.ts";
+import { join, resolve } from "../../../test_util/std/path/mod.ts";
 export {
   assert,
   assertEquals,
@@ -81,3 +81,8 @@ export function execCode2(code: string) {
     },
   };
 }
+
+export function tmpUnixSocketPath(): string {
+  const folder = Deno.makeTempDirSync();
+  return join(folder, "socket");
+}
diff --git a/cli/tsc/dts/lib.deno.unstable.d.ts b/cli/tsc/dts/lib.deno.unstable.d.ts
index 11510d144..4d909a789 100644
--- a/cli/tsc/dts/lib.deno.unstable.d.ts
+++ b/cli/tsc/dts/lib.deno.unstable.d.ts
@@ -1948,6 +1948,127 @@ declare namespace Deno {
     shutdown(): Promise<void>;
   }
 
+  export interface ServeUnixOptions {
+    /** The unix domain socket path to listen on. */
+    path: string;
+
+    /** An {@linkcode AbortSignal} to close the server and all connections. */
+    signal?: AbortSignal;
+
+    /** The handler to invoke when route handlers throw an error. */
+    onError?: (error: unknown) => Response | Promise<Response>;
+
+    /** The callback which is called when the server starts listening. */
+    onListen?: (params: { path: string }) => void;
+  }
+
+  /** Information for a unix domain socket HTTP request.
+   *
+   * @category HTTP Server
+   */
+  export interface ServeUnixHandlerInfo {
+    /** The remote address of the connection. */
+    remoteAddr: Deno.UnixAddr;
+  }
+
+  /** A handler for unix domain socket HTTP requests. Consumes a request and returns a response.
+   *
+   * If a handler throws, the server calling the handler will assume the impact
+   * of the error is isolated to the individual request. It will catch the error
+   * and if necessary will close the underlying connection.
+   *
+   * @category HTTP Server
+   */
+  export type ServeUnixHandler = (
+    request: Request,
+    info: ServeUnixHandlerInfo,
+  ) => Response | Promise<Response>;
+
+  /**
+   * @category HTTP Server
+   */
+  export interface ServeUnixInit {
+    /** The handler to invoke to process each incoming request. */
+    handler: ServeUnixHandler;
+  }
+
+  /** Serves HTTP requests with the given option bag and handler.
+   *
+   * You can specify the socket path with `path` option.
+   *
+   * ```ts
+   * Deno.serve(
+   *   { path: "path/to/socket" },
+   *   (_req) => new Response("Hello, world")
+   * );
+   * ```
+   *
+   * You can stop the server with an {@linkcode AbortSignal}. The abort signal
+   * needs to be passed as the `signal` option in the options bag. The server
+   * aborts when the abort signal is aborted. To wait for the server to close,
+   * await the promise returned from the `Deno.serve` API.
+   *
+   * ```ts
+   * const ac = new AbortController();
+   *
+   * const server = Deno.serve(
+   *    { signal: ac.signal, path: "path/to/socket" },
+   *    (_req) => new Response("Hello, world")
+   * );
+   * server.finished.then(() => console.log("Server closed"));
+   *
+   * console.log("Closing server...");
+   * ac.abort();
+   * ```
+   *
+   * By default `Deno.serve` prints the message
+   * `Listening on path/to/socket` on listening. If you like to
+   * change this behavior, you can specify a custom `onListen` callback.
+   *
+   * ```ts
+   * Deno.serve({
+   *   onListen({ path }) {
+   *     console.log(`Server started at ${path}`);
+   *     // ... more info specific to your server ..
+   *   },
+   *   path: "path/to/socket",
+   * }, (_req) => new Response("Hello, world"));
+   * ```
+   *
+   * @category HTTP Server
+   */
+  export function serve(
+    options: ServeUnixOptions,
+    handler: ServeUnixHandler,
+  ): Server;
+  /** Serves HTTP requests with the given option bag.
+   *
+   * You can specify an object with the path option, which is the
+   * unix domain socket to listen on.
+   *
+   * ```ts
+   * const ac = new AbortController();
+   *
+   * const server = Deno.serve({
+   *   path: "path/to/socket",
+   *   handler: (_req) => new Response("Hello, world"),
+   *   signal: ac.signal,
+   *   onListen({ path }) {
+   *     console.log(`Server started at ${path}`);
+   *   },
+   * });
+   * server.finished.then(() => console.log("Server closed"));
+   *
+   * console.log("Closing server...");
+   * ac.abort();
+   * ```
+   *
+   * @category HTTP Server
+   */
+  export function serve(
+    options: ServeUnixInit & ServeUnixOptions,
+  ): Server;
+
   /**
    * A namespace containing runtime APIs available in Jupyter notebooks.
    *
diff --git a/ext/http/00_serve.js b/ext/http/00_serve.js
index aeebca93d..e74e1e71f 100644
--- a/ext/http/00_serve.js
+++ b/ext/http/00_serve.js
@@ -34,11 +34,12 @@ import {
   ReadableStreamPrototype,
   resourceForReadableStream,
 } from "ext:deno_web/06_streams.js";
-import { listen, TcpConn } from "ext:deno_net/01_net.js";
+import { listen, listenOptionApiName, TcpConn } from "ext:deno_net/01_net.js";
 import { listenTls } from "ext:deno_net/02_tls.js";
 const {
   ArrayPrototypePush,
   Error,
+  ObjectHasOwn,
   ObjectPrototypeIsPrototypeOf,
   PromisePrototypeCatch,
   Symbol,
@@ -272,6 +273,13 @@ class InnerRequest {
   }
 
   get remoteAddr() {
+    const transport = this.#context.listener?.addr.transport;
+    if (transport === "unix" || transport === "unixpacket") {
+      return {
+        transport,
+        path: this.#context.listener.addr.path,
+      };
+    }
     if (this.#methodAndUri === undefined) {
       if (this.#slabId === undefined) {
         throw new TypeError("request closed");
@@ -337,8 +345,9 @@ class CallbackContext {
   serverRid;
   closed;
   closing;
+  listener;
 
-  constructor(signal, args) {
+  constructor(signal, args, listener) {
     // The abort signal triggers a non-graceful shutdown
     signal?.addEventListener(
       "abort",
@@ -352,6 +361,7 @@ class CallbackContext {
     this.scheme = args[1];
     this.fallbackHost = args[2];
     this.closed = false;
+    this.listener = listener;
   }
 
   close() {
@@ -519,11 +529,29 @@ function serve(arg1, arg2) {
   }
 
   const wantsHttps = options.cert || options.key;
+  const wantsUnix = ObjectHasOwn(options, "path");
   const signal = options.signal;
   const onError = options.onError ?? function (error) {
     console.error(error);
     return internalServerError();
   };
+
+  if (wantsUnix) {
+    const listener = listen({
+      transport: "unix",
+      path: options.path,
+      [listenOptionApiName]: "Deno.serve",
+    });
+    const path = listener.addr.path;
+    return serveHttpOnListener(listener, signal, handler, onError, () => {
+      if (options.onListen) {
+        options.onListen({ path });
+      } else {
+        console.log(`Listening on ${path}`);
+      }
+    });
+  }
+
   const listenOpts = {
     hostname: options.hostname ?? "0.0.0.0",
     port: options.port ?? 8000,
@@ -581,7 +609,11 @@ function serve(arg1, arg2) {
  * Serve HTTP/1.1 and/or HTTP/2 on an arbitrary listener.
  */
 function serveHttpOnListener(listener, signal, handler, onError, onListen) {
-  const context = new CallbackContext(signal, op_http_serve(listener.rid));
+  const context = new CallbackContext(
+    signal,
+    op_http_serve(listener.rid),
+    listener,
+  );
   const callback = mapToCallback(context, handler, onError);
 
   onListen(context.scheme);
@@ -593,7 +625,11 @@ function serveHttpOnListener(listener, signal, handler, onError, onListen) {
  * Serve HTTP/1.1 and/or HTTP/2 on an arbitrary connection.
  */
 function serveHttpOnConnection(connection, signal, handler, onError, onListen) {
-  const context = new CallbackContext(signal, op_http_serve_on(connection.rid));
+  const context = new CallbackContext(
+    signal,
+    op_http_serve_on(connection.rid),
+    null,
+  );
   const callback = mapToCallback(context, handler, onError);
 
   onListen(context.scheme);
diff --git a/ext/net/01_net.js b/ext/net/01_net.js
index 9cdcdb78c..f2bf5e7df 100644
--- a/ext/net/01_net.js
+++ b/ext/net/01_net.js
@@ -19,6 +19,7 @@ const {
   ObjectPrototypeIsPrototypeOf,
   PromiseResolve,
   SymbolAsyncIterator,
+  Symbol,
   SymbolFor,
   TypeError,
   TypedArrayPrototypeSubarray,
@@ -416,6 +417,8 @@ class Datagram {
   }
 }
 
+const listenOptionApiName = Symbol("listenOptionApiName");
+
 function listen(args) {
   switch (args.transport ?? "tcp") {
     case "tcp": {
@@ -427,7 +430,10 @@ function listen(args) {
       return new Listener(rid, addr);
     }
     case "unix": {
-      const { 0: rid, 1: path } = ops.op_net_listen_unix(args.path);
+      const { 0: rid, 1: path } = ops.op_net_listen_unix(
+        args.path,
+        args[listenOptionApiName] ?? "Deno.listen",
+      );
       const addr = {
         transport: "unix",
         path,
@@ -505,6 +511,7 @@ export {
   Datagram,
   listen,
   Listener,
+  listenOptionApiName,
   resolveDns,
   shutdown,
   TcpConn,
diff --git a/ext/net/ops_unix.rs b/ext/net/ops_unix.rs
index beb41bb4a..7a5da9fa1 100644
--- a/ext/net/ops_unix.rs
+++ b/ext/net/ops_unix.rs
@@ -194,15 +194,17 @@ where
 pub fn op_net_listen_unix<NP>(
   state: &mut OpState,
   #[string] path: String,
+  #[string] api_name: String,
 ) -> Result<(ResourceId, Option<String>), AnyError>
 where
   NP: NetPermissions + 'static,
 {
   let address_path = Path::new(&path);
-  super::check_unstable(state, "Deno.listen");
+  super::check_unstable(state, &api_name);
   let permissions = state.borrow_mut::<NP>();
-  permissions.check_read(address_path, "Deno.listen()")?;
-  permissions.check_write(address_path, "Deno.listen()")?;
+  let api_call_expr = format!("{}()", api_name);
+  permissions.check_read(address_path, &api_call_expr)?;
+  permissions.check_write(address_path, &api_call_expr)?;
   let listener = UnixListener::bind(address_path)?;
   let local_addr = listener.local_addr()?;
   let pathname = local_addr.as_pathname().map(pathstring).transpose()?;