[ansible] Generate the /etc/hosts with Ansible

hosts

#!/usr/bin/env python

import json

data = {
    "openstack": {
        "children": [
            "controller"
        ], 
        "vars": {
            "envFile": "{{ inventory_dir }}/global.yml"
        }
    }, 
    "controller": {
        "hosts": [
            "ctrl01.uoi.io", 
            "ctrl02.uoi.io", 
            "ctrl03.uoi.io"
        ], 
        "vars": {
            "envFile": "{{ inventory_dir }}/global.yml"
        }
    }, 
    "_meta": {
        "hostvars": {
            "ctrl01.uoi.io": {
                "ansible_host": "10.0.0.60"
            }, 
            "ctrl02.uoi.io": {
                "ansible_host": "10.0.0.61"
            }, 
            "ctrl03.uoi.io": {
                "ansible_host": "10.0.0.62"
            }
        }
    }
}

print json.dumps(data)

hosts.j2

# {{ ansible_managed }}
127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6

{% for item in play_hosts %}
{% set short_name = item.split('.') %}
{{ hostvars[item]['ansible_host'] }}  {{ item }} {{ short_name[0] }}
{% endfor %}

hosts.yml

---
# tasks/hosts.yml
- name: Generate /etc/hosts file
  template:
    src=etc/hosts.j2
    dest=/etc/hosts

Hi,

This how I generate my /etc/hosts file based on my dynamic inventory generated from a database.

Hope it helps.