Ansible is a powerful tool for automating IT infrastructure. One of its features is the ability to use templates to generate dynamic configuration files. This is particularly useful when deploying multiple servers with similar configurations. In this article, we will explore how to use ansible templates to generate configuration files.
First, let’s define what a template is. A template is a text file that contains variables, loops, and conditional statements. These variables are replaced with their values when the template is processed by Ansible.
To create a template, we need to use the Jinja2 template engine. Jinja2 is a fast and efficient templating engine that can handle complex logic and expressions. We can use Jinja2 syntax to create templates that are easy to read and maintain.
To use a template in Ansible, we need to create a .j2 file that contains the template code. For example, we can create a template for an Nginx configuration file like this:
“`
server {
listen {{ nginx_port }};
server_name {{ nginx_server_name }};
root {{ nginx_root }};
}
“`
In this template, we have defined three variables: `nginx_port`, `nginx_server_name`, and `nginx_root`. These variables will be replaced with their values when the template is processed.
To use this template in an Ansible playbook, we need to use the `template` module. Here’s an example:
“`
– name: Create Nginx configuration file
template:
src: nginx.conf.j2
dest: /etc/nginx/conf.d/nginx.conf
owner: root
group: root
mode: 0644
“`
In this code snippet, we are using the `template` module to generate an Nginx configuration file. The `src` parameter specifies the location of the template file, and the `dest` parameter specifies the location where the generated file will be saved. We also specify the owner, group, and mode of the generated file.
We can pass variables to the template using the `vars` parameter. For example:
“`
– name: Create Nginx configuration file
template:
src: nginx.conf.j2
dest: /etc/nginx/conf.d/nginx.conf
owner: root
group: root
mode: 0644
vars:
nginx_port: 80
nginx_server_name: example.com
nginx_root: /var/www/html
“`
In this example, we are passing values for the `nginx_port`, `nginx_server_name`, and `nginx_root` variables.
In conclusion, Ansible templates are a powerful feature that allows us to generate dynamic configuration files. With the help of Jinja2 syntax and the `template` module, we can create templates that are easy to read and maintain. Templates are particularly useful when deploying multiple servers with similar configurations, as they allow us to automate the process of generating configuration files.
