Ansible Primer

** Michael P. Reilly (arcege@gmail.com/mreilly@ptc.com) **

This is meant to be an accelerated lesson for learning Ansible.

The lessons are written to be interactive and self-paced; to read through the playbooks, roles and related files as hte lesson progresses.

Quick-start

source init.sh
ansible-playbook operator.yml -e lesson=10-playbooks
ansible-playbook 10-playbooks/plays.yml
ansible-playbook 10-playbooks/flow.yml
ansible-playbook 10-playbooks/task-status.yml
ansible-playbook operator.yml -e lesson=20-variables
...

Lessons

Each lesson will have a lesson.md file that walks the user through the steps. Some steps may be manual to show the difficulty, but most will be running Ansible commands.

• Playbooks - learn the basic structure and flow of playbooks, plays and tasks
• Variables - learn about variables, facts and registers
• Adhoc - use ad-hoc commands to execute on a range of hosts
• Roles - modularized execution
• Inventory - hosts, groups and related variables
• Idempotence - desired state as opposed to functional ends
• Limiting
  • Limit by Tag - limit tasks to be executed
  • Limit by Host - limit hosts to be executed against
• Development
  • Debugging - how to handle issues
  • Testing - unit and functional testing

Each lesson has its own environment, see Environment below, to orchestrate and provision hosts for that lesson to perform against.

Assumptions

To make learning this easier, I've made some assumptions:

• Know a little about YAML and its format
• Know a little about Jinja2 templating
• Have Python 3 installed
• Have docker installed and running - special privileges are not required
• Have a Bourne-like shell running on a Linux-like system
  • Bash and Zsh are supported
  • CentOS, Ubuntu and Darwin (macos) are supported

Setup

Initialization

In the top level of the directory, load the init.sh script.

$ source init.sh

This will create and activate a Python Virtualenv and populate it with the tools needed. If called from within a virtualenv, it will be used instead of creating a new one.

Completion

When finished with the lessons, you can tear down the environment using:

$ ansible-playbook operator.yml -e operation=finish

Environment

The primer uses Docker to create containers used during each lesson. In each lesson, containers are started and then destroyed when moving to the next lesson.

There is an Ansible playbook at the top level called operator.yml. The lesson variable needs to be given on the command line with the lesson to be provisioned.

$ ansible-playbook operator.yml -e lesson=10-playbooks

If the lesson is not being changed, then the variable does not need to be specified on the command-line.

Documentation

The documentation is in markdown files. Run mkdocs serve to create a local web server to view.

Failures

There will be some lessons that have explicit, deliberate failures. Those will be shown in the lesson documents. Others may occur for other reasons; for those, my apologies.

Supporting files

The following files can be ignored for the lessons, they are for the environment to use.

• setup/
• LICENSE