Overlord

A runner for your scripts so you don’t have to deploy them. 🚀

Overlord takes a root directory (or a root URL) containing a bunch of JS or TS scripts and serves them using a lightweight http server. Each time overlord receives a request, it spawns a Worker which imports the scripts and runs it in an isolated environment.

Experimental. Use at your own risk. 💥

Background

Deno is very suitable for running scripts. It’s a single executable, you don’t have to manage dependencies, it has top-level await, and runs Typescript by default. I wanted to add upon that by providing an easy and secure way to call these scripts remotely.

Usage

CLI

1. Install it: deno --unstable install --allow-net --allow-read https://deno.land/x/overlord/cli.ts
2. Use it: overlord -r https://deno.land/x/overlord/cli.ts/examples
3. Try it: curl localhost:8080/hello_world.ts

Programatically

import { Overlord } from "https://deno.land/x/overlord/mod.ts"

const overlord = new Overlord({
    rootPath: "https://deno.land/x/overlord/cli.ts/examples",
    port: 5000,
});

overlord.start();

Features

1. Zero dependancies (unless you count deno std).
2. Lightweight and fast; with an ~80mb executable and just using deno std http server.
3. Easy configuration.
4. Deploy anywhere; your local machine, a server, in docker or kubernetes, or even serverless (with some caching considerations).

When Should I Use This?

1. You want to run scripts in an isolated environment.
2. You want a self-hostable alternative to deno deploy.
3. Lazy load and build your scripts.

Roadmap

1. Remove unstable features once Deno 2.0 is released.
2. Support WebAssembly.
3. Resource limits for workers. This is not planned to be supported by Deno at the moment, so we will have to find a workaround.