Allow node adapter to be configured to have node server listen to socket path instead of host and port

Author: matths

packages/adapter-node/index.js

@@ -25,6 +25,7 @@ const pipe = promisify(pipeline);
  *   out?: string;
  *   precompress?: boolean;
  *   env?: {
+ *     path?: string;
  *     host?: string;
  *     port?: string;
  *   };
@@ -34,7 +35,7 @@ const pipe = promisify(pipeline);
 export default function ({
 	out = 'build',
 	precompress,
-	env: { host: host_env = 'HOST', port: port_env = 'PORT' } = {},
+	env: { path: path_env = 'SOCKET_PATH', host: host_env = 'HOST', port: port_env = 'PORT' } = {},
 	esbuild: esbuildConfig
 } = {}) {
 	/** @type {import('@sveltejs/kit').Adapter} */
@@ -58,7 +59,9 @@ export default function ({
 			utils.copy(files, '.svelte-kit/node');
 			writeFileSync(
 				'.svelte-kit/node/env.js',
-				`export const host = process.env[${JSON.stringify(
+				`export const path = process.env[${JSON.stringify(
+					path_env
+				)}] || false;\nexport const host = process.env[${JSON.stringify(
 					host_env
 				)}] || '0.0.0.0';\nexport const port = process.env[${JSON.stringify(port_env)}] || 3000;`
 			);

packages/adapter-node/package.json

@@ -29,6 +29,7 @@
 		"@sveltejs/kit": "workspace:*",
 		"c8": "^7.7.2",
 		"compression": "^1.7.4",
+		"http-proxy": "^1.18.1",
 		"node-fetch": "^3.0.0-beta.9",
 		"polka": "^1.0.0-next.15",
 		"rollup": "^2.55.0",

packages/adapter-node/src/index.js

@@ -1,12 +1,20 @@
 // TODO hardcoding the relative location makes this brittle
 import { init, render } from '../output/server/app.js'; // eslint-disable-line import/no-unresolved
-import { host, port } from './env.js'; // eslint-disable-line import/no-unresolved
+import { path, host, port } from './env.js'; // eslint-disable-line import/no-unresolved
 import { createServer } from './server';
 
 init();
 
-const instance = createServer({ render }).listen(port, host, () => {
-	console.log(`Listening on ${host}:${port}`);
-});
+const instance = createServer({ render });
+
+if (path) {
+	instance.listen(path, () => {
+		console.log(`Listening on ${path}`);
+	});
+} else {
+	instance.listen(port, host, () => {
+		console.log(`Listening on ${host}:${port}`);
+	});
+}
 
 export { instance };

packages/adapter-node/tests/smoke_path.js

@@ -0,0 +1,77 @@
+import { test } from 'uvu';
+import { createServer } from '../src/server.js';
+import * as assert from 'uvu/assert';
+import fetch from 'node-fetch';
+import httpProxy from 'http-proxy';
+import fs from 'fs';
+
+const PROXY_PORT = 9090;
+const { SOCKET_PATH = '/tmp/socket' } = process.env;
+const DEFAULT_SERVER_OPTS = { render: () => {} };
+
+function cleanupSocketFile() {
+	if (fs.existsSync(SOCKET_PATH)) {
+		fs.unlinkSync(SOCKET_PATH);
+	}
+}
+
+function createProxy() {
+	const proxy = httpProxy.createProxyServer({
+		target: {
+			socketPath: SOCKET_PATH
+		},
+		xfwd: true,
+		secure: false
+	});
+	proxy.listen(PROXY_PORT);
+	return proxy;
+}
+
+function startServer(opts = DEFAULT_SERVER_OPTS) {
+	const server = createServer(opts);
+	return new Promise((fulfil, reject) => {
+		server.listen(SOCKET_PATH, (err) => {
+			if (err) {
+				reject(err);
+			}
+			fulfil(server);
+		});
+	});
+}
+
+test('starts a server listening on a path (domain socket file)', async () => {
+	const server = await startServer();
+	assert.ok('server started');
+	server.server.close();
+	cleanupSocketFile();
+});
+
+test('serves a 404 via path', async () => {
+	const server = await startServer();
+	const proxy = createProxy();
+	const res = await fetch(`http://localhost:${PROXY_PORT}/nothing`);
+	assert.equal(res.status, 404);
+	server.server.close();
+	proxy.close();
+	cleanupSocketFile();
+});
+
+test('responses with the rendered status code via path', async () => {
+	const server = await startServer({
+		render: () => {
+			return {
+				headers: 'wow',
+				status: 203,
+				body: 'ok'
+			};
+		}
+	});
+	const proxy = createProxy();
+	const res = await fetch(`http://localhost:${PROXY_PORT}/wow`);
+	assert.equal(res.status, 203);
+	server.server.close();
+	proxy.close();
+	cleanupSocketFile();
+});
+
+test.run();