Advanced Template Customization | Templates

Introduction

Templates in Ansible are a powerful way to manage configuration files across multiple systems. By using Jinja2 templating engine, Ansible allows you to create dynamic, customized configurations that can be deployed to any number of systems.

Basic Template Structure

Ansible uses the Jinja2 templating engine to handle variables and logic within templates. A basic template might look like this:

server_name={{ inventory_hostname }}
listen 80;
root /var/www/{{ inventory_hostname }};

Using Conditionals

You can use conditionals within your templates to create more complex configurations. For example:

{% if ansible_os_family == 'Debian' %}
apt-get update
{% elif ansible_os_family == 'RedHat' %}
yum update
{% endif %}

Looping in Templates

Looping allows you to iterate over a list of items within your template. Here is an example:

server {
    listen 80;
    server_name {{ inventory_hostname }};
    {% for site in nginx_sites %}
    location /{{ site.name }} {
        proxy_pass http://{{ site.proxy }};
    }
    {% endfor %}
}

Advanced Variable Usage

You can also perform advanced operations with variables. For example, you can use filters to transform data:

{{ my_list | join(', ') }}

Output: item1, item2, item3

Including External Files

You can include external files within your templates. This is useful for breaking down large configurations into manageable pieces:

{% include 'common_settings.j2' %}

Template Inheritance

Template inheritance allows you to create a base template and extend it with other templates. This helps in maintaining a consistent structure across multiple configurations:

{% extends "base.j2" %}
{% block content %}
    This is the content block.
{% endblock %}

Conclusion

Advanced template customization in Ansible provides a robust framework for managing configuration files. By leveraging Jinja2's powerful features, you can create dynamic, scalable, and maintainable configurations to deploy across your infrastructure.

Advanced Template Customization in Ansible