'File not found' exact path in nginx and php-fpm

Question

Sometimes when configuring nginx and php-fpm I get message "File not found." I know this is beacause of wrong parameter SCRIPT_FILENAME, e.g.:

fastcgi_param   SCRIPT_FILENAME  /some/path$fastcgi_script_name;

I wonder is there a way to get exact full path of file which is cannot be found by php-fpm?

My php5-fpm.log has nothing, but:

[06-Jan-2014 11:14:33] NOTICE: configuration file /etc/php5/fpm/php-fpm.conf test is successful
[06-Jan-2014 11:27:01] NOTICE: configuration file /etc/php5/fpm/php-fpm.conf test is successful

I've tried to change log_level option in php-fpm.conf to error and debug, but result remains the same

P.S. This line:

add_header X-My-Header /some/path$fastcgi_script_name;

doesn't do the trick, because add_header only works with successful responses, as I've read here

There is the nginx module, that allows to set header even with fail responses, but I think it should be an easier way to get file path.

Thank you.

Answer 1

The solution would be the logging needed variables by nginx using log_format.

In the simplest case it may look like this (paste this code into http context):

log_format mylog '$fastcgi_script_name';
access_log  /var/log/nginx/access.log  mylog;

Then you can see results in access log file (in my case /var/log/nginx/access.log).

Another solution is to compile nginx with HttpHeadersMoreModule. This module allows you to manipulate http headers with much more flexibility than with nginx default add_header directive. So to view $fastcgi_script_name value you can write:

location ~ \.php$ {
    more_set_headers    "x-debug-header: $fastcgi_script_name";
    fastcgi_pass        127.0.0.1:9000;
    ...
}

Then you can see headers in Google Chrome DevTools in the Network tab (or similar tools in other browsers).

P.S. with HttpHeadersMoreModule you can also rewrite a Server header, if you need of course:

more_set_headers    "Server: my_server";

Good luck!