Nextjs returns a 308 redirect on

[gltched-usr]

Hey,
my app is hosted behind Cloudflare and works fine.

Now I’ve added a subdomain (es.mydomain.com) that isn’t proxied through Cloudflare because Cloudflare caused issues with webhooks. Instead, I let Traefik handle it directly.

I set up Traefik to rewrite requests like this:

- traefik.http.routers.https-1-pcgkgsw8ogk0808sgocsc0os-clipify.rule=Host(`es.mydomain.com`) && PathPrefix(`/`)
- traefik.http.routers.https-1-pcgkgsw8ogk0808sgocsc0os.middlewares=gzip,es-internal-rewrite
- traefik.http.middlewares.es-internal-rewrite.replacepathregex.regex=^/(.*)$
- traefik.http.middlewares.es-internal-rewrite.replacepathregex.replacement=/eventsub/$$1

Problem:

When I visit https://es.mydomain.com/, instead of serving the response from /eventsub, Next.js responds with a 308 Permanent Redirect to /eventsub.

So I always end up with:
Location: /eventsub

Instead of Next.js just handling the /eventsub route internally.

Whats causing this 308 redirect?

[MatyasZERO]

By default, Next.js normalizes paths by removing the trailing slash. For example, /eventsub/ is automatically redirected to /eventsub. This is why you’re seeing the redirect.

traefik.http.middlewares.es-internal-rewrite.replacepathregex.replacement=/eventsub/$$1
You are replacing it to /eventsub/ so nextjs is trying to remove the slash.

To fix this problem, update your next.config.js like this:

module.exports = {
  trailingSlash: true,
};

With this setting, Next.js will keep the trailing slash in URLs, and the redirect will no longer occur.