https://docs.ansible.com/ansible/latest/user_guide/intro_adhoc.html

ansible all -m ping -vvv
ansible hostname -m ping -vvv
ansible --inventory /etc/ansible/hosts myhost.local -i hosts -m ping
ansible-doc user
ansible-inventory --graph Ubuntu16_4                                                         #show members of group "Ubuntu16_4"
ansible-inventory --graph                                                                    #show groups
ansible myhost.local -a "apt-get update" -u ansible --become
ansible mygroup -a "/sbin/reboot"
ansible mygroup -a "/sbin/reboot" -f 10 -u username --become                                 #run command in root-context trough "--become"

/etc/ansible/ansible.cfg