1 FastCGI sent in stderr: “Primary script unknown”

Question

My first time using Nginx, but I am more than familiar with Apache and Linux. I am using an existing project and when ever I am trying to see the index.php I get a 404 File not

Answer 1

"Primary script unknown" is caused by SELinux security context.

client get the response

File not found.

nginx error.log has the following error message

*19 FastCGI sent in stderr: "Primary script unknown" while reading response header from upstream

so just change security context type of web root folder to httpd_sys_content_t

chcon -R -t httpd_sys_content_t /var/www/show

there are 3 users for nginx/php-fpm config

/etc/nginx/nginx.conf

user nobody nobody;  ### `user-1`, this is the user run nginx woker process
...
include servers/*.conf;

/etc/nginx/servers/www.conf

location ~ \.php$ {
#   fastcgi_pass 127.0.0.1:9000;  # tcp socket
    fastcgi_pass unix:/var/run/php-fpm/fpm-www.sock;  # unix socket
    fastcgi_index index.php;
    fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
    include fastcgi_params;
}

/etc/php-fpm.d/www.conf

[www]
user = apache  ### `user-2`, this is the user run php-fpm pool process
user = apache

;listen = 127.0.0.1:9000  # tcp socket
listen = /var/run/php-fpm/fpm-www.sock  # unix socket

listen.onwer = nobody  ### `user-3`, this is the user for unix socket, like /var/run/php-fpm/fpm-www.sock
listen.group = nobody  # for tcp socket, these lines can be commented
listen.mode = 0660

user-1 and user-2 is not necessary to be the same.

for unix socket, user-1 need to be the same as user-3, as nginx fastcgi_pass must have read/write permission on the unix socket.

otherwise nginx will get 502 Bad Gateway, and nginx error.log has the following error message

*36 connect() to unix:/var/run/php-fpm/fpm-www.sock failed (13: Permission denied) while connecting to upstream