group_vars and host_vars

Variables next to the inventory

Instead of cramming variables into the inventory file, create group_vars/<group>.yml and host_vars/<host>.yml beside it. Ansible loads them automatically. Variables in group_vars/all.yml apply everywhere, while group_vars/web.yml applies to the web group and host_vars/web1.yml only to that host. This keeps data separate from logic and makes environment differences easy to see in code review.

A typical layout

Environment-specific values live in the inventory directory of that environment.

inventories/
  staging/
    hosts.ini
    group_vars/
      all.yml        # app_env: staging
      web.yml        # http_port: 8080
  production/
    hosts.ini
    group_vars/
      all.yml        # app_env: production
      web.yml        # http_port: 80
playbooks/site.yml
roles/...

One playbook, many environments

Run ansible-playbook -i inventories/staging site.yml and later -i inventories/production. The playbook stays identical; only the data changes.

Quick check: Where do you put variables that apply only to the web group?

• ansible.cfg only
• group_vars/web.yml
• A random hosts file
• A comment in the playbook