Nginx

Nginx needs a few lines more than Caddy: WebSocket upgrades for /socket.io/, the forwarded headers and a larger body limit (its default is 1 MB). Read the overview first if you have not.

Install Nginx

On Debian and Ubuntu:

sudo apt install nginx

Site configurations go in /etc/nginx/sites-available/ and are enabled with a link in /etc/nginx/sites-enabled/. Other distributions use /etc/nginx/conf.d/*.conf.

HTTP

Create /etc/nginx/sites-available/fileship:

map $http_upgrade $connection_upgrade {
    default upgrade;
    '' close;
}

server {
    listen 80;
    listen [::]:80;
    server_name files.example.com;

    client_max_body_size 0;

    location / {
        proxy_pass http://127.0.0.1:3000;
        proxy_http_version 1.1;

        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-Fileship-Client-IP $remote_addr;
        proxy_set_header X-Forwarded-Proto $scheme;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection $connection_upgrade;

        proxy_request_buffering off;
        proxy_read_timeout 300s;
        proxy_send_timeout 300s;
    }
}

Enable it and reload:

sudo ln -s /etc/nginx/sites-available/fileship /etc/nginx/sites-enabled/
sudo nginx -t
sudo systemctl reload nginx

127.0.0.1:3000 is the built-in proxy with Docker and the app itself without Docker; the configuration is the same.

What the lines do:

• client_max_body_size 0 turns off Nginx's body limit, so ShareX and scripts can upload large files in one request. Set a size such as 2G to cap it, but keep it above the chunk size (25 MB by default).
• proxy_request_buffering off streams uploads to Fileship instead of writing them to a temporary file first.
• Upgrade and Connection let socket.io switch to WebSockets. The map sends Connection: close for normal requests.
• $proxy_add_x_forwarded_for appends the client address to X-Forwarded-For, which is how Fileship gets the client IP.
• X-Fileship-Client-IP $remote_addr overwrites a header Fileship trusts from proxies. Keep it, or a visitor could send their own and pretend to have another IP address.

HTTPS with Certbot

Start with the HTTP configuration above, point your domain's DNS at the server and open ports 80 and 443. Then let Certbot get a certificate and change the configuration for you:

sudo apt install certbot python3-certbot-nginx
sudo certbot --nginx -d files.example.com

Certbot adds the listen 443 ssl lines, the certificate paths and a redirect from HTTP to HTTPS, and renews the certificate automatically. If you prefer to write the HTTPS server yourself, this is the full result:

map $http_upgrade $connection_upgrade {
    default upgrade;
    '' close;
}

server {
    listen 80;
    listen [::]:80;
    server_name files.example.com;

    return 301 https://$host$request_uri;
}

server {
    listen 443 ssl;
    listen [::]:443 ssl;
    http2 on;
    server_name files.example.com;

    ssl_certificate /etc/letsencrypt/live/files.example.com/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/files.example.com/privkey.pem;

    client_max_body_size 0;

    location / {
        proxy_pass http://127.0.0.1:3000;
        proxy_http_version 1.1;

        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-Fileship-Client-IP $remote_addr;
        proxy_set_header X-Forwarded-Proto $scheme;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection $connection_upgrade;

        proxy_request_buffering off;
        proxy_read_timeout 300s;
        proxy_send_timeout 300s;
    }
}

http2 on; needs Nginx 1.25.1 or newer; on older versions write listen 443 ssl http2; instead.

Behind another TLS terminator

When a load balancer or CDN in front of Nginx terminates HTTPS and talks to Nginx over HTTP, $scheme is http. Pass on the protocol it sends instead: add this map next to the other one and change the X-Forwarded-Proto line:

map $http_x_forwarded_proto $forwarded_proto {
    default $http_x_forwarded_proto;
    '' $scheme;
}

proxy_set_header X-Forwarded-Proto $forwarded_proto;

Only do this when Nginx is reachable from that terminator alone, because clients could otherwise send their own header. Setting Link protocol to Always HTTPS is the alternative (see Link protocol).

Nginx in Docker

Run the official image next to the Fileship stack and reach the host's port 3000 through host.docker.internal:

services:
    nginx:
        image: nginx:alpine
        restart: unless-stopped
        ports:
            - '80:80'
        extra_hosts:
            - 'host.docker.internal:host-gateway'
        volumes:
            - ./fileship.conf:/etc/nginx/conf.d/default.conf:ro

Use one of the configurations above as fileship.conf, with proxy_pass http://host.docker.internal:3000;.

Nginx Proxy Manager

In Nginx Proxy Manager, add a proxy host with the scheme http, the forward host and port of Fileship (the host's address and 3000) and Websockets Support on. In the Advanced tab add:

client_max_body_size 0;
proxy_request_buffering off;

Nginx Proxy Manager sets Host, X-Forwarded-For and X-Forwarded-Proto itself. This setup was not tested.

Check it

Follow After the proxy works.