Testing ansible locally with Docker

Introduction

Configuration management is a critical aspect of IT infrastructure, and Ansible has emerged as a powerful tool for automating this process. While Ansible excels at managing remote systems, testing playbooks and roles locally can be cumbersome. In this article, we’ll explore a streamlined approach to testing Ansible locally using Docker, allowing you to iterate and validate configurations more efficiently.

Pre-requisites

• Docker
• Ansible

And that’s it! With these two, you can start along.

Preface

Before diving into Ansible playbooks, we need to create an SSH server image for Docker. This step is essential for setting up the necessary environment to run Ansible locally.

Ansible with Docker container

If you went to test your changes already and did not follow this tutorial, you can also download the code from this repo: https://github.com/anmolb12/docker-ansible

Creating SSH Server image

We’ll use Ubuntu for our image and set up the SSH server. Create a Dockerfile with the following content:

Build the image using the command:

docker build -t ubuntu-ssh-server .

Now, run a container from this image:

docker run -d -p 2222:22 --name ssh_container ubuntu-ssh-server

You now have a running SSH server. Test the connection with:

ssh -p 2222 node@localhost

Amazing, so now let’s move to the next part.

Run ansible-playbook on the docker container

Next, let’s create an Ansible project. We need two files: ansible-playbook.yaml and inventory.ini.

inventory.ini

[docker]
localhost become_ansible_user=node become_ansible_password=node1234 ansible_user=node ansible_password=node1234 ansible_ssh_port=2222

ansible-playbook.yaml

- name: Docker Playbook
  hosts: all
  become: true
  tasks:
    - name: Update apt cache
      apt:
        update_cache: yes

    - name: Install Apache
      apt:
        name: apache2
        state: present

In this file, we are installing apache2 in host.

Run the playbook on the Docker container:

ansible-playbook -i inventory.ini playbook.yaml --ask-become-pass

Voila! You now have Apache server installed on the Docker container using Ansible.

Conclusion

This simple setup can be extended to use multiple containers, making debugging and testing Ansible playbooks locally even more straightforward. Explore the possibilities for scaling and adapting this approach to your specific needs.