How to create a host Inventory using Ansible?

Updated: 11 October 2026 · Applies to: Ansible (ansible-core 2.16+) on Ubuntu 24.04, Debian 12, AlmaLinux 9 and Rocky Linux 9

An inventory lists the servers Ansible manages. Ansible can also collect facts from each server (OS, memory, disks, IPs) to build an overview of your whole estate. These steps use current Ansible (ansible-core 2.16 or newer).

A static inventory

# inventory.yml
all:
  children:
    web:
      hosts:
        web1.example.com:
        web2.example.com:
    db:
      hosts:
        db1.example.com:
  vars:
    ansible_user: admin

ansible-inventory -i inventory.yml --graph      # show groups and hosts
ansible-inventory -i inventory.yml --list       # everything as JSON

Collect facts from all hosts

ansible all -i inventory.yml -m ansible.builtin.setup --tree facts/

This writes one JSON file per host into facts/ with the OS version, CPU, memory, disks and network. Filter with -a "filter=ansible_distribution*".

Turn facts into an overview

• The ansible-cmdb tool (installed with pipx) generates an HTML overview from that folder: ansible-cmdb facts/ > overview.html. It is no longer actively developed; check it works with your data.
• Or write a small playbook that uses ansible.builtin.template to create a CSV or Markdown table from the facts you need.

Tip: For cloud servers, dynamic inventory plugins read the server list directly from the provider's API, so the inventory is always current.