deno-http-worker

Similarly to deno-vm, deno-http-worker lets you securely spawn Deno http servers.

Usage

import { newDenoHTTPWorker } from "@valtown/deno-http-worker";

let worker = await newDenoHTTPWorker(
    `export default {
        async fetch(req: Request): Promise<Response> {
            return Response.json({ ok: req.url });
        },
    }`,
    { printOutput: true, runFlags: ["--allow-net"] },
);

const req = await worker.request({
    url: "https://hello/world?query=param",
    method: "GET",
});
const body = await req.body.json();

console.log(body); // => {"ok":"https://hello/world?query=param"}

worker.terminate();

Internals

Tip

This package globally patches Deno.upgradeWebSocket to enable websocket proxying. You can provide your own bootstrap script if different behavior is desired.

Deno-http-worker connects to the Deno process over a Unix socket via undici to make requests. As a result, the worker does not provide an address or url, but instead returns undici.ResponseData that uses undici.Pool.request under the hood, but modifies the request attributes to work over the socket, and we expose parts of request and response interface.

You can also connect to the Deno process over a WebSocket connection, which uses the same undici.Pool. We modify the inbound Request objects to preserve various headers. Unfortunately Deno doesn't let you copy a request and then modify properties, so we patch Deno.upgradeWebSocket when you use the WebSockets functionality to use the original request for the upgrade, which may be slightly different.

If you need more advanced usage here, or run into bugs, please open an issue.