Loop in file template - Ansible module template - Generate hosts file

How to use for loop in Ansible module template to generate/etc/myhosts file with IP address, hostname, and short name from Ansible inventory. Ansible Playbook, Jinja2 template, and with Magic Variables included.

How to use a loop in a file template to the target host with Ansible?

This is extremely useful for service configuration files, placeholder web pages, reports, and so much more use cases.

I'm going to show you a live Playbook with some simple Ansible code.

I'm Luca Berton and welcome to today's episode of Ansible Pilot.

Ansible loop in file template

ansible.builtin.template

Template a file out to a target host

ansible_managed, template_host, template_uid, template_path, template_fullpath, template_destpath, and template_run_date

Today we're talking about the Ansible module template.

The full name is ansible.builtin.template, it's part of ansible-core and is included in all Ansible installations.

It templates a file out to a target host. Templates are processed by the Jinja2 templating language.

Also you could use also some special variables in your templates: ansible_managed, template_host, template_uid, template_path, template_fullpath, template_destpath, and template_run_date.

It supports a large variety of Operating Systems.

For basic text formatting, use the [Ansible ansible.builtin.copy module](/articles/create-a-text-file-ansible-module-copy) or for [empty file Ansible ansible.builtin.file module](/articles/create-an-empty-file-ansible-module-file).

For Windows, use the ansible.windows.win_template module instead.

Parameters

src path - template ("templates/" dir)

dest path - target location

validate string - validation command before ("%s")

backup boolean - no/yes

mode/owner/group - permission

setype/seuser/selevel - SELinux

Let me highlight the most useful parameters for the template module.

The only required parameters are "src" and "dest".

The "src" parameter specifies the template file name. Templates usually are stored under "templates" directories with ".j2" file extension.

The "dest" parameter specifies the path where to render the template to on the remote machine.

The "validate" parameters allow you to specify the validation command to run before copying it into place. It's very useful with configuration files for services.

Please note that the special escape sequence "%s" is going to be expanded by Ansible with the destination path.

If the "backup" parameter is enabled Ansible creates a backup file including the timestamp information before copying it to the destination.

Let me also highlight that we could also specify the permissions and SELinux properties.

## Playbook

Loop in file template with Ansible Playbook.

You could find more information about Magic Variables: https://docs.ansible.com/ansible/latest/reference_appendices/special_variables.html

code

generate_myhosts.yml

``yaml


---
name: template module Playbook
  hosts: all
  become: true
  tasks:
    - name: generate /etc/myhosts file
      ansible.builtin.template:
        src: templates/hosts.j2
        dest: /etc/myhosts
        owner: root
        group: root
        mode: '0644'

hosts.j2