Zabbix frontend went "Configuration file error - Permission denied."

[DaylightDies]

Hello everyone

We have a pretty fresh instance of Zabbix (less than 3 weeks old). Everything was running smoothly, until today.



I was welcomed with this screen.

We're running Zabbix on:
Ubuntu 22.04
nginx/1.18.0
PHP 8.1.2
Latest postgresql (it's on a different server, but working fine)
Openssl 3.0.2

I checked the logs for zabbix server and it looks ok overall. For error.log in /var/log/nginx I noticed lines like:

2022/07/26 11:13:58 [crit] 1626#1626: *2 SSL_read() failed (SSL: error:0A000126:SSL routines::unexpected eof while reading) while processing HTTP/2 connection, client: my_ip_address, server: 0.0.0.0:443
2022/07/26 11:18:03 [crit] 1626#1626: *15 SSL_read() failed (SSL: error:0A000126:SSL routines::unexpected eof while reading) while processing HTTP/2 connection, client: my_ip_address, server: 0.0.0.0:443

[DaylightDies]

Ok, I figured it out.

I was suspecting that SSL error may not be related to this issue and - in fact - it's not.

I had navigate to /etc/zabbix/web and change ownership & permission of a file zabbix.conf.php from www-data:www-data to root:root & changing permission from 600 to 644