I am seeing a strange issue where my php.ini is not used if I do not explicitly pass it to php-fpm when starting it.

This is the upstart script I am using:

start on (filesystem and net-device-up IFACE=lo)
stop on runlevel [016]

pre-start script
    mkdir -p /run/php
end script


expect fork
respawn
exec /usr/local/php/sbin/php-fpm --fpm-config /etc/php/php-fpm.conf

If PHP is started with the above, my php.ini is never used, even though it is in Configuration File (php.ini) Path.

This is the relevant part from phpinfo():

Configuration File (php.ini) Path           /etc/php/
Loaded Configuration File                   (none)
Scan this dir for additional .ini files     (none)
Additional .ini files parsed                (none) 

If I modify the last line of the upstart script to point php-fpm to php.ini explicitly:

exec /usr/local/php/sbin/php-fpm --fpm-config /etc/php/php-fpm.conf -c /etc/php/php.ini

Then we see that the php.ini is loaded:

Configuration File (php.ini) Path           /etc/php/
Loaded Configuration File                   /etc/php/php.ini
Scan this dir for additional .ini files     (none)
Additional .ini files parsed                (none) 

Why is this the case? Is this a quirk in php-fpm?

Minor update: This also seems to be a problem for php5-fpm installed using apt-get.

I did a test install in a Ubuntu Server 12.04 virtual machine by running the following:

sudo apt-get install nginx php5-fpm

PHP-FPM and nginx were started after installation and everything seemed fine. I then uncommented php's settings in nginx's configuration and placed a test phpinfo() file to inspect PHP's settings.

The relevant bits are:

Configuration File (php.ini) Path           /etc/php5/fpm
Loaded Configuration File                   (none)
Scan this dir for additional .ini files     /etc/php5/fpm/conf.d
Additional .ini files parsed                /etc/php5/fpm/conf.d/10-pdo.ini 

I noted that no php.ini was loaded either. However, if I go to /etc/php5/fpm, I can see that a php.ini exists. I also checked the start up scripts for PHP-FPM and the -c parameter was not used to link the ini file to PHP. This can potentially be confusing for people who would expect php.ini to be loaded automatically by PHP-FPM.