Ansible

---
name: ansible
description: |
  Ansible automation reference for playbooks, roles, inventory, variables, and modules.
  Includes Proxmox VE and Docker integration via community.general and community.docker collections.
  Use when writing playbooks, troubleshooting Ansible runs, or designing automation workflows.
  Triggers: ansible, playbook, inventory, role, task, handler, vars, jinja2, galaxy, proxmox_kvm, proxmox_lxc, docker_container, docker_compose.
agent: ansible-expert
---

# Ansible Skill

Ansible automation reference for configuration management and application deployment.

## Quick Reference

```bash
# Test connectivity
ansible all -m ping
ansible <group> -m ping

# Run playbook
ansible-playbook playbook.yml
ansible-playbook playbook.yml -l <host>    # Limit to host
ansible-playbook playbook.yml --check      # Dry-run
ansible-playbook playbook.yml -vvv         # Verbose

# Tags
ansible-playbook playbook.yml --tags "deploy"
ansible-playbook playbook.yml --skip-tags "backup"
ansible-playbook playbook.yml --list-tags

# Variables
ansible-playbook playbook.yml -e "var=value"
ansible-playbook playbook.yml -e "@vars.yml"

# Ad-hoc commands
ansible <group> -m shell -a "command"
ansible <group> -m copy -a "src=file dest=/path"
ansible <group> -m apt -a "name=package state=present"

# Galaxy
ansible-galaxy collection install -r requirements.yml
ansible-galaxy role install <role>
```

## Reference Files

Load on-demand based on task:

| Topic | File | When to Load |
|-------|------|--------------|
| Playbook Structure | [playbooks.md](references/playbooks.md) | Writing playbooks |
| Inventory | [inventory.md](references/inventory.md) | Host/group configuration |
| Variables | [variables.md](references/variables.md) | Variable precedence, facts |
| Modules | [modules.md](references/modules.md) | Common module reference |
| Troubleshooting | [troubleshooting.md](references/troubleshooting.md) | Common errors, debugging |

### Proxmox Integration

| Topic | File | When to Load |
|-------|------|--------------|
| Proxmox Modules | [proxmox/modules.md](references/proxmox/modules.md) | VM/LXC management via API |
| Proxmox Auth | [proxmox/authentication.md](references/proxmox/authentication.md) | API tokens, credentials |
| Proxmox Gotchas | [proxmox/gotchas.md](references/proxmox/gotchas.md) | Common issues, workarounds |
| Dynamic Inventory | [proxmox/dynamic-inventory.md](references/proxmox/dynamic-inventory.md) | Auto-discover VMs/containers |

### Docker Integration

| Topic | File | When to Load |
|-------|------|--------------|
| Docker Deployment | [docker/deployment.md](references/docker/deployment.md) | Containers, images, networks, volumes |
| Compose Patterns | [docker/compose-patterns.md](references/docker/compose-patterns.md) | Roles, templates, multi-service stacks |
| Docker Troubleshooting | [docker/troubleshooting.md](references/docker/troubleshooting.md) | Common errors, debugging |

## Playbook Quick Reference

```yaml
---
- name: Deploy application
  hosts: webservers
  become: true
  vars:
    app_port: 8080

  pre_tasks:
    - name: Validate requirements
      ansible.builtin.assert:
        that:
          - app_secret is defined

  tasks:
    - name: Install packages
      ansible.builtin.apt:
        name: "{{ item }}"
        state: present
      loop:
        - nginx
        - python3

    - name: Deploy config
      ansible.builtin.template:
        src: app.conf.j2
        dest: /etc/app/app.conf
      notify: Restart app

  handlers:
    - name: Restart app
      ansible.builtin.service:
        name: app
        state: restarted

  post_tasks:
    - name: Verify deployment
      ansible.builtin.uri:
        url: "http://localhost:{{ app_port }}/health"
```

## Variable Precedence (High to Low)

1. Extra vars (`-e "var=value"`)
2. Task vars
3. Block vars
4. Role/include vars
5. Play vars
6. Host facts
7. host_vars/
8. group_vars/
9. Role defaults

## Directory Structure

```text
ansible/
├── ansible.cfg          # Configuration
├── inventory/
│   └── hosts.yml        # Inventory
├── group_vars/
│   ├── all.yml          # All hosts
│   └── webservers.yml   # Group-specific
├── host_vars/
│   └── server1.yml      # Host-specific
├── roles/
│   └── app/
│       ├── tasks/
│       ├── handlers/
│       ├── templates/
│       ├── files/
│       └── defaults/
├── playbooks/
│   └── deploy.yml
├── templates/
│   └── config.j2
└── requirements.yml     # Galaxy dependencies
```

## Idempotency Checklist

- [ ] Tasks produce same result on repeated runs
- [ ] No `changed_when: true` unless necessary
- [ ] Use `state: present/absent` not `shell` commands
- [ ] Check mode (`--check`) shows accurate changes
- [ ] Second run shows all "ok" (no changes)