Ansible Tutorial inside Docker

This repository provides a self-contained Ansible environment using Docker. It includes an Ansible control node and a target managed node, allowing you to practice Ansible playbooks without installing anything on your host machine other than Docker.

Prerequisites

• Docker
• Docker Compose

Getting Started

1. Start the environment:

   docker-compose up -d --build

   This will start two containers:

   • ansible-tutorial-control-1: The control node where you will run Ansible commands.
   • ansible-tutorial-target-1: The target node that Ansible will manage.

2. Access the Control Node:

   docker-compose exec control bash

   You are now inside the container with Ansible installed. The project directory is mounted at /ansible.

3. Run Example Playbooks:

   Verify connectivity with the ping playbook:

   ansible-playbook playbooks/01-ping.yml

   Install Nginx on the target node:

   ansible-playbook playbooks/02-setup-webserver.yml

   Create multiple users using loops and variables:

   ansible-playbook playbooks/03-create-users.yml

   Demonstrate handlers (restart service on change):

   ansible-playbook playbooks/04-handlers-demo.yml

   Demonstrate conditionals:

   ansible-playbook playbooks/05-conditionals.yml

   Read and print Ansible facts:

   ansible-playbook playbooks/06-read-facts.yml

   Filtering for Specific Facts Since the full output is usually hundreds of lines long, you can use the filter argument to find exactly what you need:

   ansible all -m setup -a "filter=ansible_distribution*" OS name and version

   ansible all -m setup -a "filter=ansible_eth*" Network interface details

   ansible all -m setup -a "filter=ansible_memtotal_mb" Total RAM available

   ansible all -m setup -a "filter=ansible_processor*" CPU details

   Use an Ansible Role to configure Nginx:

   ansible-playbook playbooks/07-use-role.yml

Files Structure

• docker/: Contains Dockerfiles for the control and target nodes.
• playbooks/: Contains example Ansible playbooks.
• inventory: Defines the hosts that Ansible manages.
• ansible.cfg: Ansible configuration file.
• docker-compose.yml: Defines the services and their relationship.

Troubleshooting

If you encounter SSH issues, ensure that the control container has successfully copied its SSH key to the target container. You can verify this by trying to SSH from control to target:

docker-compose exec control ssh target

If it asks for a password, something went wrong with the setup command in docker-compose.yml. You can manually fix it by running:

docker-compose exec control sshpass -p 'root' ssh-copy-id -o StrictHostKeyChecking=no root@target