Why is my site downloaded instead of running? - nginx

Question

I'm trying to install Wordpress on a Ubuntu 18.04 on a subdomain. I set the Nginx files on sites-available, but I get a 502 error on browser because Wordpress is using a .php file type for the index, so I added "index.php" on the list in sites-available. Well after adding "index.php" on the list when I try to access the URL in browser it downloads a file named with the subdomain address.
Here's my code in sites-available
server {
listen 80;
listen [::]:80;
root /var/www/apt;
# Add index.php to the list if you are using PHP
index index.html index.htm index.nginx-debian.html index.php;
server_name apt.forrum.ro;
location / {
# First attempt to serve request as file, then
# as directory, then fall back to displaying a 404.
try_files $uri $uri/ =404;
}
}
Please let me know how to fix it.

Answer 1

This is simplified, basically Nginx uses the try_files directive to serve the file to user in the folder. This is why your php file is being sent to the user, it's then downloaded rather than shown as browsers don't really know how to show PHP to the user.
What you need to do is tell Nginx to run the file. In the case of PHP you can use FastCGI. There are many guides to doing this on ubuntu such as This One.
Once you have it installed, all the directives for FastCGI are described by Nginx themselves Here.
Their example is posted here:
location ~ [^/]\.php(/|$) {
fastcgi_split_path_info ^(.+?\.php)(/.*)$;
if (!-f $document_root$fastcgi_script_name) {
return 404;
}
# Mitigate https://httpoxy.org/ vulnerabilities
fastcgi_param HTTP_PROXY "";
fastcgi_pass 127.0.0.1:9000;
fastcgi_index index.php;
# include the fastcgi_param setting
include fastcgi_params;
# SCRIPT_FILENAME parameter is used for PHP FPM determining
# the script name. If it is not set in fastcgi_params file,
# i.e. /etc/nginx/fastcgi_params or in the parent contexts,
# please comment off following line:
# fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
}