Ansible

TL;DR

Was: Agentenloses IT-Automatisierungstool für Konfigurationsmanagement und Deployment.

Warum: Keine Agenten erforderlich, einfache YAML-Syntax, idempotente Operationen, riesige Modulbibliothek.

Quick Start

Installieren:

# macOS
brew install ansible

# Linux (pip)
pip install ansible

# Überprüfen
ansible --version

Erster Befehl (ad-hoc):

# Localhost pingen
ansible localhost -m ping

# Befehl auf Remote-Hosts ausführen
ansible all -i "server1,server2," -m shell -a "uptime"

Inventory-Datei (hosts.ini):

[webservers]
web1.example.com
web2.example.com

[databases]
db1.example.com

Cheatsheet

Befehl	Beschreibung
ansible all -m ping	Alle Hosts pingen
ansible-playbook play.yml	Playbook ausführen
ansible-playbook -i hosts play.yml	Mit Inventory
ansible-galaxy install role	Rolle installieren
ansible-vault encrypt file	Datei verschlüsseln
ansible-doc -l	Module auflisten

Gotchas

Basic playbook

# playbook.yml
---
- name: Configure web servers
  hosts: webservers
  become: yes

  tasks:
    - name: Install nginx
      apt:
        name: nginx
        state: present
        update_cache: yes

    - name: Start nginx
      service:
        name: nginx
        state: started
        enabled: yes

    - name: Copy config
      template:
        src: nginx.conf.j2
        dest: /etc/nginx/nginx.conf
      notify: Restart nginx

  handlers:
    - name: Restart nginx
      service:
        name: nginx
        state: restarted

Variables

# Im Playbook
vars:
  http_port: 80
  max_clients: 200

# In vars-Datei
# vars/main.yml
app_name: myapp
app_version: "1.0.0"

# Variablen verwenden
- name: Create directory
  file:
    path: "/opt/{{ app_name }}"
    state: directory

Common modules

# Dateioperationen
- file: path=/tmp/test state=directory mode=0755
- copy: src=file.txt dest=/tmp/file.txt
- template: src=config.j2 dest=/etc/app/config

# Paketverwaltung
- apt: name=nginx state=present
- yum: name=httpd state=latest

# Service-Verwaltung
- service: name=nginx state=started enabled=yes

# Befehle
- command: /usr/bin/make
- shell: echo $HOME > /tmp/home.txt

Roles structure

roles/
  webserver/
    tasks/main.yml
    handlers/main.yml
    templates/
    files/
    vars/main.yml
    defaults/main.yml

Next Steps

• Ansible-Dokumentation - Offizielle Dokumentation
• Ansible Galaxy - Rollen-Repository
• Ansible-Beispiele - Beispiel-Playbooks
• Ansible Best Practices - Tipps