Simple Ansible Inventory

The idea is to keep an Ansible inventory simple, clean and easily readable. Each host will only have to be written one time and you'll not have to define each group before using it.

Prerequisites

Simple Ansible Inventory works with python2 and python3. Only the package pyyaml is needed. You can install it using one of the following commands

pip install -r requirements.txt

or

pip install pyyaml

How to use

Alone

./simple-ansible-inventory.py --list

With ansible

ansible-inventory -i simple-ansible-inventory.py --list

To work properly, simple-ansible-inventory.py needs inventory file(s) to read. There's two possibilities :

• By default, simple-ansible-inventory.py will look in its folder and in all of its subfolder for inventory yaml file(s)
• If the environment variable ANSIBLE_YAML_INVENTORY is defined, simple-ansible-inventory.py will attempt to read the inventory file in the environment variable and only this one

Directory layout

The directory layout followed is given by the Ansible best pratices. https://docs.ansible.com/ansible/latest/user_guide/playbooks_best_practices.html#directory-layout

Inventory files

You can find inventory file examples in inventory_file_1.yml and inventory_file_2.yml

An inventory file is a yaml file starting with the following header

---
#### YAML inventory file

In this inventory file, you only define hosts and groups associated to this host. There's no group definition, a group is automatically created when associated to an host.

Example:

If you define the following host

hosts:
  - host: luke-01.example.com
    groups: [group_1, datacenter_1]

• the host luke-01.example.com will be created
• groups group_1 and datacenter_1 will be created
• groups group_1 and datacenter_1 will be associated to the host luke-01.example.com

Group vars

Following Ansible best practices, all group vars have to be defined in the group_vars folder. If you want to create the variable group: Rebels for the group group_1, you have to create the file group_vars/group_1.yml with the following content:

---
group: Rebels

Host vars

There's two possibilities to define host vars

1. In the inventory file
2. In the host_vars folder (following Ansible best practices)

In the inventory file

If you want to create the variable lightsaber: blue for the host obi-wan-02.example.com, you have to set hostvars for the host in the inventory file:

- host: obi-wan-02.example.com
  hostvars:
    lightsaber: blue
  groups: [group_1, datacenter_1]

In the host_vars folder (following Ansible best practices)

Following Ansible best practices, host vars have to be defined in the host_vars folder. If you want to create the variable force_side: Sith for the host darth-vader-01.example.com, you have to create the file host_vars/darth-vader-01.example.com.yml with the following content:

---
force_side: Sith

And that's it !