server {
    listen 80;
    server_name _;

    root /usr/share/nginx/html;
    index index.html;

    # Large mailbox zip backups (multi-GB).
    client_max_body_size 20g;
    client_body_timeout 3600s;

    location /api/ {
        proxy_pass http://backend:8000/api/;
        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-Forwarded-Proto $scheme;
        # Stream upload body to backend instead of buffering in nginx.
        proxy_request_buffering off;
        proxy_read_timeout 3600s;
        proxy_send_timeout 3600s;
        proxy_connect_timeout 60s;
    }

    location = /index.html {
        add_header Cache-Control "no-cache";
    }

    location / {
        try_files $uri $uri/ /index.html;
    }
}