I looked at Discourse and loved the UI and features. I naively assumed ldap support a given (really even if it not there, how much will it take).
I looked at various topics and various discourse ldap plugins on github. Alas none worked. Hence I made a try of my own (dont know anything about ruby, forget about rails).
Finally I got a working plugin. Most people should be able to use it with any code change (by just modiying the plgin settings).