Bootstrap FreeKB - Ansible - yaml inventory plugin
Ansible - yaml inventory plugin

Updated:   |  Ansible articles

Tasks are run against target servers. Some Ansible documentation refers to the target servers as "hosts".


After a clean install of Ansible, the "inventory" directive in ansible.cfg is commented out, like this.

#inventory = /path/to/hosts


In this scenario, the default hosts file is /etc/ansible/hosts and the default hosts file is completely commented out. If you were to issue command ansible all -m ping, the following would be displayed. Likewise, if you were to uncomment the "inventory" directive in ansible.cfg without defining your inventory, the following would be displayed.

[WARNING]: provided hosts list is empty, only localhost is available. Note that the implicit localhost does not match 'all'


Typically, target servers are defined in the default hosts file or your own inventory file. Sometimes, the "inventory" directive in ansible.cfg is uncommented and updated to point to the directory where the default hosts file or your own inventory file will be located.

Additionally, Ansible uses inventory plugins to parse inventory. For example, ansible.cfg may have the following. Let's say you have yaml as one of the enabled_plugins in ansible.cfg.

enable_plugins = host_list, yaml, ini


This also assumes you have defined your inventory in a yaml file, such as hosts.yml. Let's say hosts.yml contains the following managed hosts (e.g. the target systems).



The ansible command with the --list-hosts and -vvv flags can be used to determine if the yaml plugin is being used.

ansible all --list-hosts -vvv


If you get something like this, this suggests you did not define yaml in ansible.cfg properly.

[WARNING]: Unable to parse /etc/ansible/hosts.yml as an inventory source


If the following is returned, the host_list plugin is being used.

Parsed /etc/ansible/hosts.yml inventory source with yaml plugin


Something like this should be returned.

Parsed /etc/ansible/hosts.yml inventory source with yaml plugin
  hosts (4):


Additionally, you may use the -i or --inventory option to point to a specific YAML file that contains your target servers.

ansible all --inventory /tmp/hosts.yml --list-hosts -vvv


Or, the ansible-inventory --list command can be used.

ansible-inventory --list


Or, the ansible-inventory --graph command can be used.

ansible-inventory --graph



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