Ansible

Installation

Installation on Fedora may require separately installing Python2 (because Python 3 is the default):

$ sudo dnf install ansible python2 libselinux-python

Terminology

Inventory is the file that holds hosts information. The default is /etc/ansible/hosts or you can provide your own using the -i option (usually -i hosts):

[webservers]
erebus.mndt.co.uk

Module are reusable, standalone scripts that can be run using ansible or from an ansible-playbook command

Group vars

• Use group_vars/mygroup to define a variables file which will be used by playbooks in the group named mygroup.
• If a host is defined in multiple groups, it will receive the variables from each group_vars/groupname file.

Best practices

Looping:

• With the release of Ansible 2.5, the recommended way to perform loops is the use the new loop keyword instead of with_X style loops.

Cookbook

Running arbitrary commands

Run DNF update cache on a host as root on nodes in the hosts file:

ansible all -m dnf -a 'update_cache=true' -i ./hosts -u root --become