I’m writing an init script (e.g. /docker-entrypoint-initdb.d/init.js) which will be executed by the mongo Docker image when the container is first created. (See the docs for the image, “Initializing a fresh instance” section.)

Within this script, I need to open a file from disk (on the container), and then insert an object into the database with that file’s content as a property. Something like this:

import fs from "fs";

let data = fs.readFileSync("/path/to/somefile.txt", { encoding: "base64" });

db.example.files.insertOne({
  filename: "somefile.txt",
  data: Binary.createFromBase64(data),
});

But this script is written for NodeJS — how can I do the same in a plain JS script executed via MongoDB directly (e.g. mongosh -f init.js)?