How can I configure Nginx as a reverse proxy for n8n on a custom port (88)?

Below is some guidance based on our documentation on configuring webhook URLs when n8n is behind a reverse proxy.

Key Points

1. Manually Set WEBHOOK_URL
   When n8n runs behind a reverse proxy (especially when the external port differs from the internal one), it doesn’t automatically generate the correct webhook URLs. You must set the environment variable so that n8n knows the full external URL, including the custom port. For example:

   BASHCopied
   export WEBHOOK_URL=https://n8n.site.io:88/

2. Reverse Proxy Host Header
   Your reverse proxy (Nginx in this case) must forward the request with the proper host headers. By default, forwarding the header without the port may cause n8n to generate webhooks that differ from what external services need. Make sure the Host header includes the port (or the URL that external clients see). For instance, in your Nginx location block you can explicitly set the header:

   NGINXCopied
   location / {
       proxy_pass http://127.0.0.1:88;
       proxy_set_header Host "n8n.site.io:88";
       proxy_set_header X-Real-IP $remote_addr;
       proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
       proxy_set_header X-Forwarded-Proto $scheme;
   }

3. Consistency with Traefik & Environment Variables
   Your provided docker-compose configuration already sets WEBHOOK_URL to include :88, which is correct. However, because Traefik is responsible for handling incoming requests on ports 80/443 inside the container, ensure that the reverse proxy (Nginx) is forwarding to the correct host and port. If the Host header gets rewritten or stripped, then external requests might not match the webhook URL as registered in n8n.

4. Note on Proxy Hops
   If you’re running several layers of reverse proxies, you may need to adjust the N8N_PROXY_HOPS environment variable. This ensures that n8n correctly parses the original request (like determining the correct protocol and host from the X-Forwarded-* headers). Check the Environment Variables documentation for details if needed.

Summary of Your Situation

• You’re running n8n in Docker, but it listens only on port 5678 inside the container.
• Traefik is exposing n8n externally on port 88 (mapping container port 80 to host port 88).
• Your docker-compose file correctly sets WEBHOOK_URL=https://${SUBDOMAIN}.${DOMAIN_NAME}:88/ so that n8n registers webhook URLs using port 88.
• Your Nginx configuration, however, must preserve this port in the forwarded request. By default, a standard proxy may forward the Host header without the :88 suffix. This mismatch causes the registered webhook URL (which includes :88) to never be hit correctly.

Action Items:

• Modify your Nginx config to explicitly set the Host header with the port (as shown above).
• Confirm that both HTTP and HTTPS locations in the Nginx config use similar settings so that the forwarded Host header matches what n8n expects.
• Test the webhook endpoint using curl with the full URL (including port) to verify it’s working.

Following these adjustments should allow n8n to correctly register and receive webhook calls without unexpected redirections or mismatches due to the custom port configuration.

Below is some guidance on how to adjust your setup so that webhook URLs and internal redirections include the custom port (88) you need for n8n. The key points are:

1. Make sure n8n’s environment is aware of the external URL (with port 88) by manually setting the WEBHOOK_URL (which you already do) and using matching values for N8N_HOST, N8N_PROTOCOL, and especially WEBHOOK_URL so that any internally generated URLs carry the port.

2. When using a reverse proxy on a non‐standard port, the proxy must pass along the actual external port. In your case, you can add a header such as X‑Forwarded‑Port so that n8n (or Traefik if that were handling redirections) “sees” that requests are coming on port 88. For example:

NGINXCopied
location / {
    proxy_pass http://127.0.0.1:88;
    proxy_set_header Host $host;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header X-Forwarded-Proto $scheme;
    proxy_set_header X-Forwarded-Port 88;
}

3. Because your reverse proxy (ISPmanager-controlled Nginx) is redirecting requests without the port information, make sure that any redirection fields (or proxy_redirect directives) rewrite the URLs so that they include “:88.” In many cases this means adding a directive like:

NGINXCopied
proxy_redirect http:// $scheme://$host:88/;

This tells Nginx to rewrite the Location headers that backend services may send.

4. Verify that your Docker configuration for n8n has the WEBHOOK_URL set to the full external URL (including port) as follows:

YAMLCopied
environment:
  - N8N_HOST=${SUBDOMAIN}.${DOMAIN_NAME}
  - N8N_PORT=5678
  - N8N_PROTOCOL=https
  - WEBHOOK_URL=https://${SUBDOMAIN}.${DOMAIN_NAME}:88/

Even though n8n is internally running on port 5678, the externally visible webhook must be the one your proxy receives (i.e. with port 88).

5. As an alternative (if possible) consider using the standard HTTP/HTTPS ports on your VPS. For instance, if you could configure your reverse proxy (or ISPmanager) to forward standard port traffic to n8n, then you could avoid these extra complications. However, if you’re forced to use port 88 for webhooks, the above changes in your Nginx configuration should help.

In summary, focus on:

• Passing the correct forwarded port header (X-Forwarded-Port 88)
• Adjusting proxy_redirect so that any Location headers or redirects include “:88”
• Ensuring your WEBHOOK_URL reflects the full external URL with port 88

Try these changes, then test whether webhooks are correctly registered and that external links include “:88”. This approach should resolve the issues you’re experiencing with reverse proxy behavior.

If problems persist, double-check that no other configuration layer (ISPmanager or Traefik) is stripping or replacing port information.