Skip to content
Cloud Kung-Fu

Facts and Templates

3 min read


In Ansible, variables and facts, along with templates, are foundational tools for creating flexible automation workflows. Variables allow you to manage and change your configurations dynamically. Facts are a special subset of variables that Ansible gathers from the remote systems, providing context-specific information. Templates enable the generation of variable-driven configuration files, making your playbooks adaptable to varied environments and scenarios.

These tools make playbooks reusable and adaptable, allowing you to avoid hard-coding values and enabling customization for different environments.

Variables & Facts

Variables allow for parameters to be modified without altering the playbook's core logic.

How variables, facts & templates work together
  • Types of Variables:

    • Boolean: True or False values.

    • List: An ordered collection of items.

    • Dictionary: Key-value pairs for complex data structures.

    • Registered Variables: Captures the output of tasks to use later in your playbook.

    • Facts: Auto-collected variables that provide details about the remote systems you are managing.

NB: Avoid conflicts in variable names by using bracket notation.

- name: Print the distribution of the target
hosts: all
curr_time: "{{ now() }}"
- name: Distro Check
msg: "The target system is {{ ansible_facts['distribution'] }}. Timestamp: {{ curr_time }}"

Templates & Files

Templates in Ansible use the Jinja2 templating language to dynamically create files using variable interpolation, loops, and conditionals.

- name: Write distro name
hosts: all
- name: Write distro name
src: distro.j2
dest: /root/distro.txt
mode: '644'
# src: location of jinja2 template file
# dest: location it will be copied to
# permissions that will be granted to the file


We're going to use the OS Family to determine whether to install NGINX of Lighttpd then we'll deploy a custom homepage to the remote host containing NGINX all without hardcoding hostnames.

  1. Clone the repo
git clone

2. Spin up the environment using docker-compose

docker compose up -d --build

3. SSH into the Ansible server

ssh -o StrictHostKeyChecking=no -o NoHostAuthenticationForLocalhost=yes root@localhost -p 2200# password: test123

4. Change directory to ansible_learn

cd ansible_learn

Variables & facts

5. Create a playbook called server_setup.yaml. Here, we'll setup NGINX & Lighttpd then output the name of the distro for each remote host

- name: Install NGINX on Debian & Lighttpd on RedHat
hosts: all
dev1: "Debian"
dev2: "RedHat"
- name: Install NGINX for Debian-based systems
name: nginx
state: present
when: ansible_facts['os_family'] == dev1
- name: Install Lighttpd for RedHat-based systems
name: lighttpd
state: present
when: ansible_facts['os_family'] == dev2
- name: Display the distribution
msg: "The server is running {{ ansible_facts['distribution'] }}"

6. Run ansible-lint

ansible-lint server_setup.yaml

7. Run the playbook

ansible-playbook --key-file /root/.ssh/id_rsa_ansible -u root -i inventory.yaml server_setup.yaml

8. Confirm that setup was successful

ssh -i /root/.ssh/id_rsa_ansible root@server3 nginx -V
ssh -i /root/.ssh/id_rsa_ansible root@server2 lighttpd -v
ssh -i /root/.ssh/id_rsa_ansible root@server1 lighttpd -v

Templates & Files

9. Create a Jinja2 template file called index.html.j2

It will get auto populated with the OS Family & Distribution.

<title>Welcome to {{ ansible_facts['os_family'] }}</title>
<h1>Server running on {{ ansible_facts['distribution'] }}</h1>

10. Create a playbook called custom_homepage.yaml

We're deploying the custom homepage created above to NGINX then restarting the server.

- name: Deploy Custom Homepage and restart
hosts: all
dev1: "Debian"
dev2: "RedHat"
- name: Create Homepage with Jinja2 Template for NGINX
src: index.html.j2
dest: /var/www/html/index.html
mode: '644'
when: ansible_facts['os_family'] == dev1
notify: restart nginx
- name: Restart NGINX
listen: "restart nginx"
name: nginx
state: restarted
when: ansible_facts['os_family'] == dev1

11. Run the linter

ansible-lint custom_homepage.yaml

12. Run the playbook

ansible-playbook --key-file /root/.ssh/id_rsa_ansible -u root -i inventory.yaml custom_homepage.yaml

13. Confirm deployment by visiting http://localhost:2203 in your browser.


Awesome effort! 🙌 We've learned how to use variables & facts in a playbook along with how to create dynamic files using templates. Next we'll look at modularization and error handling. Til then, take care!

© 2024 by Cloud Kung-Fu. All rights reserved.
Theme by LekoArts