A PHP-based web site on a server that I manage was failing to load. It worked a few months ago when I set it up and the owner didn’t notice that it was failing. When I looked at the error log I got these messages.
[Wed Aug 08 07:45:21.627045 2018] [proxy:error] [pid 32113:tid 139735343294208] (2)No such file or directory: AH02454: FCGI: attempt to connect to Unix domain socket /run/php/php7.2-fpm.sock (*) failed
[Wed Aug 08 07:45:21.627334 2018] [proxy_fcgi:error] [pid 32113:tid 139735343294208] [client 64.91.53.183:36745] AH01079: failed to make connection to backend: httpd-UDS
Since it said that fpm.sock failed, I thought that maybe the mod was no longer enabled so I tried a2enmod proxy_fcgi but it said that it was already enabled.
There was some info on dependencies on various help sites, so I figured that at some point an aptitude safe-upgrade command might have messed things up. So I figured that running these commands might help, and it did.
sudo apt-get update
sudo apt-get upgradeReading through the install messages I noticed this:
Setting up php7.2-fpm (7.2.7-0ubuntu0.18.04.2) ...
Package apache2 is not configured yet. Will defer actions by package php7.2-fpm.
Replacing config file /etc/php/7.2/fpm/php.ini with new version
NOTICE: Not enabling PHP 7.2 FPM by default.
NOTICE: To enable PHP 7.2 FPM in Apache2 do:
NOTICE: a2enmod proxy_fcgi setenvif
NOTICE: a2enconf php7.2-fpmSo it looks like proxy_fcgi somehow got enabled and was causing problems. It is a small site with little traffic, so I decided to leave well enough alone and not enable the mod.