This documentation page will not go into how to use Ansible or how to write Ansible playbooks, since Ansible is a complete deployment and configuration management system that is beyond the scope of Vagrant documentation.
The first component of a successful Ansible provisioner setup is the Ansible playbook which contains the steps that should be run on the guest. Ansible's
[playbook documentation](https://docs.ansible.com/playbooks.html) goes into great detail on how to author playbooks, and there are a number of [best practices](https://docs.ansible.com/playbooks_best_practices.html) that can be applied to use Ansible's powerful features effectively.
You can of course target other operating systems that do not have YUM by changing the playbook tasks. Ansible ships with a number of [modules](https://docs.ansible.com/modules.html) that make running otherwise tedious tasks dead simple.
The `playbook` option is strictly required by both Ansible provisioners ([`ansible`](/docs/provisioning/ansible.html) and [`ansible_local`](/docs/provisioning/ansible_local.html)), as illustrated in this basic Vagrantfile` configuration:
Since an Ansible playbook can include many files, you may also collect the related files in a [directory structure](https://docs.ansible.com/playbooks_best_practices.html#directory-layout) like this:
When using Ansible, it needs to know on which machines a given playbook should run. It does this by way of an [inventory](https://docs.ansible.com/intro_inventory.html) file which lists those machines. In the context of Vagrant, there are two ways to approach working with inventory files.
The first and simplest option is to not provide one to Vagrant at all. Vagrant will generate an inventory file encompassing all of the virtual machines it manages, and use it for provisioning machines.
Note that the generated inventory file is uploaded to the guest VM in a subdirectory of [`tmp_path`](/docs/provisioning/ansible_local.html), e.g. `/tmp/vagrant-ansible/inventory/vagrant_ansible_local_inventory`.
As of Vagrant 1.8.0, the [`host_vars`](/docs/provisioning/ansible_common.html#host_vars) option can be used to set [variables for individual hosts](https://docs.ansible.com/ansible/intro_inventory.html#host-variables) in the generated inventory file (see also the notes on group variables below).
The [`groups`](/docs/provisioning/ansible_common.html#groups) option can be used to pass a hash of group names and group members to be included in the generated inventory file.
As of Vagrant 1.8.0, it is also possible to specify [group variables](https://docs.ansible.com/ansible/intro_inventory.html#group-variables), and group members as [host ranges (with numeric or alphabetic patterns)](https://docs.ansible.com/ansible/intro_inventory.html#hosts-and-groups).
- Prior to Vagrant 1.7.3, the `ansible_ssh_private_key_file` variable was not set in generated inventory, but passed as command line argument to `ansible-playbook` command.
- The generation of group variables blocks (e.g. `[group1:vars]`) is only possible since Vagrant 1.8.0. Note however that setting variables directly in the inventory is not the [preferred practice in Ansible](https://docs.ansible.com/intro_inventory.html#splitting-out-host-and-group-specific-data). If possible, group (or host) variables should be set in `YAML` files stored in the `group_vars/` or `host_vars/` directories in the playbook (or inventory) directory instead.
- Unmanaged machines and undefined groups are not added to the inventory, to avoid useless Ansible errors (e.g. *unreachable host* or *undefined child group*)
- [Host range patterns (numeric and alphabetic ranges)](https://docs.ansible.com/ansible/intro_inventory.html#hosts-and-groups) will not be validated by Vagrant. As of Vagrant 1.8.0, host range patterns will be added as group members to the inventory anyway, this might lead to errors in Ansible (e.g *unreachable host*).
With the [`inventory_path`](/docs/provisioning/ansible_common.html#inventory_path) option, you can reference a specific inventory resource (e.g. a static inventory file, a [dynamic inventory script](https://docs.ansible.com/intro_dynamic_inventory.html) or even [multiple inventories stored in the same directory](https://docs.ansible.com/intro_dynamic_inventory.html#using-multiple-inventory-sources)). Vagrant will then use this inventory information instead of generating it.
- The machine names in `Vagrantfile` and `ansible.inventory_path` files should correspond, unless you use `ansible.limit` option to reference the correct machines.
- The SSH host addresses (and ports) must obviously be specified twice, in `Vagrantfile` and `ansible.inventory_path` files.
- Sharing hostnames across Vagrant host and guests might be a good idea (e.g. with some Ansible configuration task, or with a plugin like [`vagrant-hostmanager`](https://github.com/smdahlen/vagrant-hostmanager)).
Certain settings in Ansible are (only) adjustable via a [configuration file](https://docs.ansible.com/intro_configuration.html), and you might want to ship such a file in your Vagrant project.
When shipping an Ansible configuration file it is good to know that:
- it is possible to reference an Ansible configuration file via `ANSIBLE_CONFIG` environment variable, if you want to be flexible about the location of this file.
