deno-with-permissions-ts

Deno with more flexible permissions specificaiton

Whats this

A proposal to allow deno users to specify permissions via an external typescript file

Motivation

• Some permissions are complex
• Some permissions needs to be expressed in a crossplatform way
• Some permissions requires knowing the internals of the application

But all theses permissions are expressable if we use Deno ecosystem, and thus this proposal

How it looks

the user can write a permissions.ts (any name), it has to export a default memeber with this signature

https://github.com/sigmaSd/deno-with-permissions-ts/blob/master/api.ts

// simple api can be improved
export interface Permissions {
  read?: string[];
  write?: string[];
  env?: string[];
  net?: string[];
}

and then the user can run his application with deno run --permissions=$path_to_permissions_file.ts user_app.ts

Example

Taking https://github.com/sigmaSd/Chef/tree/permissions as an example, here are its permissions https://github.com/sigmaSd/Chef/blob/permissions/permissions.ts

import { Chef } from "./src/lib.ts";
import { Permissions } from "https://raw.githubusercontent.com/sigmaSd/deno-with-permissions-ts/master/api.ts";

const getEnvPermission = () => {
  switch (Deno.build.os) {
    case "linux": {
      return ["XDG_CACHE_HOME", "HOME"];
    }
    case "darwin": {
      return ["HOME"];
    }
    case "windows":
      return ["LOCALAPPDATA"];
  }
};

const permissions: Permissions = {
  read: [Chef.dbPath, Chef.binPath], // uses internal chef dbPath and binPath
  write: [Chef.dbPath, Chef.binPath],
  env: getEnvPermission(),
  net: ["github.com"],
};

export default permissions;

Can I test this right now?

First install a wrapper around deno, with this idea implemented:

deno install --unstable -A -n deno2 https://github.com/sigmaSd/deno-with-permissions-ts/raw/master/main.ts

Then you can try with the chef repo example:

deno2  run --print-generated-permissions=true --permissions=https://github.com/sigmaSd/Chef/raw/permissions/permissions.ts https://github.com/sigmaSd/Chef/raw/permissions/example.ts