OpenLDAP. Have been running that as the backend of several of my services since 2015.
I use it for authentication/authorization, either directly or via Authelia, as well as the backend storage for my DNS, DHCP, Kerberos, email servers, and a few internal / self-built applications. I even registered an official IANA PEN so my custom LDAP schema are properly implemented. It’s setup with a 4-way multi-master replication strategy and highly available via two load balancers in different data centers (plus one locally).
Runner up is Nginx as I’ve been running it for just as long or a bit longer, and it also underpins most of my services in some way (at least as the frontend proxy/WAF).
OpenLDAP. Have been running that as the backend of several of my services since 2015.
I use it for authentication/authorization, either directly or via Authelia, as well as the backend storage for my DNS, DHCP, Kerberos, email servers, and a few internal / self-built applications. I even registered an official IANA PEN so my custom LDAP schema are properly implemented. It’s setup with a 4-way multi-master replication strategy and highly available via two load balancers in different data centers (plus one locally).
Runner up is Nginx as I’ve been running it for just as long or a bit longer, and it also underpins most of my services in some way (at least as the frontend proxy/WAF).