域名同一文件路径，不同的域名指向不同的robots文件

load different robots in the same one "server" block

location ~ /robots.txt
{
if ($host = 'first.domain') {
rewrite ^/robots\.txt /path/to/another/robots.txt last;
}
}

location ~ /robots.txt
{
if ($host ~ .*nfancy.nl) {
rewrite ^/robots\.txt /nl_robots.txt last;
}
}