#Nagios 4.X
Configure:
You have a basic configuration in default_config folder. Extract this file to your local drive and edit. When you run this container you need attach this folder.
Configure MAIL:
You need edit file notification.cfg in config.d/commands.d folder with your configuration data.
Usage:
To run container:
docker run --rm -p 80:80 -v /YOUR_CONFIGURATION_FOLDER:/usr/local/nagios/etc --name nagios alferez/nagios:latest
You can see the full article at in Monitorizando con Nagios y docker