FORM.IO — nginx reversed proxy under ‘subfolder’ in order to host multiple node.js apps. i.e. http://yourserver/formio/

location /formio/ {

// rewrite to remove the subfolder
rewrite ^/formio/(.*)$ /$1 break;

proxy_pass http://127.0.0.1:3001;

proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection ‘upgrade’;
proxy_set_header Host $host;
proxy_cache_bypass $http_upgrade;

proxy_set_header X-Real-IP $remote_addr;
proxy_set_header HOST $http_host;
proxy_set_header X-NginX-Proxy true;

}