[solved] Reboot of server causes PHP5-FPM failure.

I'm working on getting my froxlor instance setup with PHP5-FPM and Nginx and was encountering an issue whereupon reboot the PHP functionality would be broken. Looking in syslog would give me about 30 lines of PHP5-FPM failing to start and then giving up. Looking in php5-fpm.log would tell me nothing useful other then the configtest passed. 
 
I eventually found a helpful message in the /var/log/upstart/php5-fpm.log file:
 
[14-May-2015 09:21:54] ERROR: unable to bind listening socket for address '/var/run/nginx/username-domain.com-php-fpm.socket': No such file or directory (2)
 
True enough the /var/run/nginx folder did not exist. I could not figure out where it was going.
 
After hair pulling research I found that the /var/run mount point is run as tmpfs and so is deleted on reboot. In order to fix this I had to ensure the directory was recreated before PHP5-FPM started. It turns out this if fairly easy with upstart. I added this stanza:
 
pre-start
        ... other stuff ...
        [ -d /var/run/nginx ] || mkdir -p /var/run/nginx
end script

to the /etc/init/nginx.conf file to have the folder created on boot.

Problem solved.