misskey/packages/backend/src/server/file/index.ts

/**
 * File Server
 */

import * as fs from 'node:fs';
import { fileURLToPath } from 'node:url';
import { dirname } from 'node:path';
import Koa from 'koa';
import cors from '@koa/cors';
import Router from '@koa/router';
import sendDriveFile from './send-drive-file.js';

const _filename = fileURLToPath(import.meta.url);
const _dirname = dirname(_filename);

// Init app
const app = new Koa();
app.use(cors());
app.use(async (ctx, next) => {
	ctx.set('Content-Security-Policy', `default-src 'none'; img-src 'self'; media-src 'self'; style-src 'unsafe-inline'`);
	await next();
});

// Init router
const router = new Router();

router.get('/app-default.jpg', ctx => {
	const file = fs.createReadStream(`${_dirname}/assets/dummy.png`);
	ctx.body = file;
	ctx.set('Content-Type', 'image/jpeg');
	ctx.set('Cache-Control', 'max-age=31536000, immutable');
});

router.get('/:key', sendDriveFile);
router.get('/:key/(.*)', sendDriveFile);

// Register router
app.use(router.routes());

export default app;