ANSIBLE TEMPLATES

Introduction

In Ansible, a template is a text file that allows dynamic content generation using variables. It is commonly used to deploy configuration files that differ slightly across multiple servers without maintaining separate files for each.

1. What is a Template?

A template is a normal text file containing placeholders written using Jinja2 syntax (double curly braces).

ServerName {{ ansible_hostname }}

• {{ variable_name }}: This value is replaced at runtime.
• Example: Server 1 becomes web-01, Server 2 becomes web-02.

2. File Extension & Usage

• Templates typically use the .j2 extension (e.g., apache.conf.j2).
• The extension is not mandatory; Ansible identifies it as a template based on the module used.

3. The Template Module

To use templates, we use the template module in the playbook:

- name: Deploy Apache configuration
  template:
    src: apache.conf.j2
    dest: /etc/apache2/apache.conf

4. Advanced Features (Jinja2 Logic)

You can use programming logic directly inside the template file:

Condition Example:

{% if ansible_os_family == "Debian" %}
PackageManager apt
{% endif %}

Loop Example:

{% for pkg in packages %}
Install {{ pkg }}
{% endfor %}

5. Key Advantages

• Reduces duplication: One template works for many servers.
• Consistency: Ensures standard configs across the infrastructure.
• Dynamic: Automatically inserts IP addresses, hostnames, or custom variables.