index.js

import { isAbsolute, join, sep } from "path";
import { existsSync, readFileSync } from "fs";
import express from "express";
import sharp from "sharp";

const port = 19092;

const allowedOutFormats = new Set([
  "jpeg",
  "png",
  "webp",
  "gif",
  "avif",
  "tiff",
]);

const app = express();

app.get("/", async (req, res) => {
  try {
    if (!req.query.filepath || !req.query.format)
      return res.status(400).send("Bad Request");

    const filePath = req.query.filepath,
      format = req.query.format;

    if (
      !isAbsolute(filePath) ||
      !existsSync(filePath) ||
      !allowedOutFormats.has(format)
    ) {
      return res.status(400).send("Bad Request");
    }

    const fileParts = filePath.split(sep),
      fileDir = fileParts.slice(0, fileParts.length - 1).join(sep),
      fileName = fileParts[fileParts.length - 1],
      fileNoExt = fileName.split(".")[0];

    if (existsSync(join(fileDir, `${fileNoExt}.${format}`)))
      return res.status(200).send("OK");

    const file = readFileSync(filePath);
    await sharp(file)
      .toFormat(format)
      .toFile(join(fileDir, `${fileNoExt}.${format}`));

    return res.status(200).send("OK");
  } catch (err) {
    console.error(err);
    return res.status(500).send("Internal Server Error");
  }
});

app.get("/health", (req, res) => res.status(200).send("OK"));

app.listen(port, () => console.log(`Server listening on port ${port}`));