Discourse does not have a file named «robots.txt». Instead, it serves the request for /robots.txt dynamically.
So how you can edit non-existent file?
There is a simple way without diving to Discourse: you can catch requests for /robots.txt using Nginx:
server {
listen 80;
server_name discourse-forum.ru;
location = /robots.txt {
root /var/www/res/discourse;
access_log off;
expires max;
break;
}
location / {
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header Host $http_host;
proxy_redirect off;
proxy_pass http://discourse_forum_ru;
}
}
Set your root
and upload custom robots.txt.