Based on the container https://registry.hub.docker.com/u/cpuguy83/nagios it includes links to enable apache ldap modules.
Basic Docker image for running Nagios.
This is running Nagios 3.5.1
You should either link a mail container in as "mail" or set MAIL_SERVER, otherwise mail will not work.
By default: - NAGIOSADMIN_USER=nagiosadmin - NAGIOSAMDIN_PASS=nagios
The Nagios Web UI is available on port 80 of the container