docker exec -u nobody -t <name of container> /usr/bin/minecraftd backup
Or if in the shell of the docker container
[root@b6d917bc09e6 /]# /usr/bin/minecraftd
This script was design to easily control any minecraft server. Quite every parameter for a given
minecraft server derivative can be altered by editing the variables in the configuration file.
Usage: minecraftd {start|stop|status|backup|restore|command <command>|console}
start Start the minecraft server
stop Stop the minecraft server
restart Restart the minecraft server
status Print some status information
backup Backup the world data
restore [filename] Restore the world data from a backup
command <command> Run the given comman at the minecraft server console
console Enter the server console through a screen session