Ansible Templates

In Ansible, a "template" typically refers to an Ansible template, which is a way to create dynamic configuration files or scripts by combining a template file with data from Ansible variables. Ansible templates use the Jinja2 templating engine to insert variables and expressions into a template, producing configuration files tailored to the specific needs of each host.

Here's an overview of how Ansible templates work:

• Template File:

  • A template file is a regular text file that includes placeholders for variables and expressions. These placeholders are enclosed in double curly braces, like {{ variable_name }}, and can include conditionals, loops, and filters.

• Variable Data:

  • In Ansible, you define variables that hold the data you want to insert into the template. These variables can be host-specific facts, inventory variables, or any custom variables you create.

• Jinja2 Templating Engine:

  • Ansible uses the Jinja2 templating engine to process the template file. It replaces the placeholders with the actual values of the variables and evaluates any expressions.

• Rendered Template:

  • The output of this template processing is a rendered configuration file, which is generated specifically for each host, based on its individual variable values.

Create a Playbook which uses Jinja template

---
- name: install required software
  hosts: webservers
  gather_facts: yes
  become: yes

  tasks:
    - name: install and start httpd services
      ansible.builtin.package:
        name: httpd
        state: present
      register: task_status

    - name: start httpd services
      ansible.builtin.service:
        name: httpd
        state: started

    - name: use template to deploy a file
      ansible.builtin.template:
        src: html.j2
        dest: /var/www/html/index.html

Create a file templates/html.j2

<html>
<body>

<h2> my operating system details are: </h2>
<br> {{ ansible_host }}
<br> {{ ansible_os_family }}
<br> {{ task_status.results }}

</body>
</html>