I’m trying to move my simple Next.js-based webapp from Vercel to DigitalOcean App Platform, but I’m encountering a problem while doing so.

My app

It has two routes:

• /
• /dashboard

The second one, /dashboard, is supposed to be available only to authorized users who have the cookie named “jwt”. For purpose of this small example, the code merely checks if the cookie named “jwt” exists. If it does, /dashboard route is presented normally. If the “jwt” cookie doesn’t exist,

This logic is realized with Next.js middleware:

import { cookies } from 'next/headers';
import { NextResponse, type NextRequest } from 'next/server';

export default  function middleware(request: NextRequest) {
  const { pathname } = request.nextUrl;
  console.log(`===> Middleware running, pathname: ${pathname}`);
  console.log(JSON.stringify(request));

  if (pathname === '/log-out') {
    const response = NextResponse.redirect(new URL('/', request.url));
    response.cookies.set('jwt', '', { path: '/', expires: new Date(0) });
    return response;
  }

  const token = cookies().get('jwt');

  if (!token && pathname !== '/') {
    console.log('No token, redirecting to /');
    return NextResponse.redirect(new URL('/', request.url));
  }
  console.log('Token found, continuing');

  return NextResponse.next();
}

export const config = {
  matcher: [
    "/((?!api|_next/static|_next/image|img/|favicon.ico).*)",
  ],
}

What I expect to happen

When the “jwt” cookie doesn’t exist, hitting /dashboard will return a 3xx response code with Location: / header, to facilitate the redirect.

When the “jwt” cookie exists, hitting /dashboard should not redirect, but instead just return a dummy “this is a dashboard” text.

This is what happens when I run the project locally, or on Vercel.

What actually happens

It doesn’t matter if the “jwt” cookie exists or not. The response I get from accessing /dashboard is always 2xx, and the Location header is missing.

This behavior completely breaks authentication in my app.

This only happens when I deploy the project on DigitalOcean App Platform.

Reproduction

GitHub Repository

I have created a very simple Next.js app (with npx create-next-app@latest mini-app-nextjs --use-npm). It allows to reproduce this issue. There’s also a Dockerfile that can be used to upload the image to DigitalOcean Container Storage:

docker build -t registry.digitalocean.com/<your-container-repository-name>/mini-app-nextjs:latest --platform linux/amd64 .

and then docker push it.

Here’s a running app, deployed on my personal account:

• orca-app-jgjmy.ondigitalocean.app/
• orca-app-jgjmy.ondigitalocean.app/dashboard