Permissions to the rescue
Last night I was changing my default tabs in chrome and decided to add my site as one of them. I figured if I did this it would push me to write more.
Imagine my shock when I was greeted with a 502 proxy error by nginx. After a little digging I found some errors in nginx error.log, specifically.unix:/var/run/php/php7.2-fpm.sock failed (13: Permission denied) while connecting to upstream
After looking online I saw some old security patches for php5 regarding process ownership and some recommendations regarding www.conf. None of them applied of course and I was stuck again. However, after a little more digging it turns out that this may have been because of an update. As such permissions were modified. It also turns out on older OSs ‘nginx’ is not by default part of the www-data group.
Now while the site was working at some point I figured the problem was because of this broken group/user relationship and thats when I found the command to re-add it to the group.
usermod -a -G www-data nginx
That worked great! Now the site was up! A new problem arose though. I needed to commit some updates to wordpress but some of the plugins would not take. Some were complaining about write permissions. The paths seemed to indicate issues with their respective home directories. A quick glance at permissions showed that either because of initial problems during my install or otherwise the ownership of the folder was set incorrectly.
A quick chown sudo chown -R www-data:
stuff
and we were back in business. Now my coffee was lukewarm and I have to get ready for work. Atleast I get to complain about things on the internet now though.