mastodon_ynh/conf/nginx.conf

 location __PATH__ {
  try_files $uri @proxy;
 }

 location @proxy {
  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 https;
  proxy_pass_header Server;
  proxy_pass http://127.0.0.1:3000;
  proxy_buffering off;
  proxy_redirect off;
  proxy_http_version 1.1;
  proxy_set_header Upgrade $http_upgrade;
  proxy_set_header Connection $connection_upgrade;
  tcp_nodelay on;
 }

 location __PATH__/api/v1/streaming {
  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 https;
  proxy_pass http://127.0.0.1:4000;
  proxy_buffering off;
  proxy_redirect off;
  proxy_http_version 1.1;
  proxy_set_header Upgrade $http_upgrade;
  proxy_set_header Connection $connection_upgrade;
  tcp_nodelay on;
 }

 error_page 500 501 502 503 504 /500.html;
}