Sub-directory Support
To run LibreNMS in a subdirectory on your Apache server, put the directives of the LibreNMS directory into the base server configuration. You can also put them into a virtual host container. For a virtual host, put the directives into the configuration file of that virtual host. On an RHEL distribution such as CentOS, the base server file is /etc/httpd/conf.d/librenms.conf. On a Debian distribution such as Ubuntu, the file is /etc/apache2/sites-available/default.
#These directives can be inside a virtual host or in the base server configuration
AllowEncodedSlashes On
Alias /librenms /opt/librenms/html
<Directory "/opt/librenms/html">
AllowOverride All
Options FollowSymLinks MultiViews
</Directory>
Change the RewriteBase directive in html/.htaccess to your subdirectory name. For LibreNMS at http://example.com/librenms/, change RewriteBase / to RewriteBase /librenms.
Then set APP_URL=/librenms/ in .env. Then run lnms config:set base_url '/librenms/'.