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

server {
    server_name sync.yourdomain.com;
    client_max_body_size 100M;
    location / {
        proxy_pass http://127.0.0.1:8787;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection $connection_upgrade;
        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_buffering off;
        proxy_read_timeout 86400s;
        proxy_send_timeout 86400s;
    }
    listen 80;
}