Improve Ansible Roles with Molecule

Ansible (1/4)

Ansible (2/4)

Ansible (3/4)

Ansible (4/4)

• Playbooks contain/connect roles
• Roles contain plays
• Plays contain tasks
• Tasks execute a module
• Tasks run sequencially
• Handlers are triggered by tasks, runs once at the end of the play

Test Automation (1/2)

• Reliable Code
• Quality (Fast feedback)
• Time and cost saving
• Faster Development Cycle (CI/CD)
• Repeatability (Test same change accross multiple environments (OS, Providers); multiple data sets)

Test Automation (2/2)

Testing options for Ansible

• Ansible tasks - Test Ansible w/ Ansible
• Test Kitchen - Test Ansible w/ Ruby
• ansible-test - Test Ansible w/ Unmaintained Python
• Molecule - Test Ansible w/ Python

Molecule (1/5)

Testing Ansible with Molecule

• Tool designed to aid in the development and testing of Ansible roles.
• Provides support for testing with multiple instances, operating systems, providers, test frameworks and testing scenarios.
• Encourages an approach that results in consistently developed roles that are well-written, easily understood and maintained.

github.com/ansible/molecule | molecule.readthedocs.io

Molecule (2/5)

Testing Ansible with Molecule

Molecule (3/5)

Testing Ansible with Molecule

• Creates nodes for testing
• Run the playbook on the nodes
• Run the playbook again to test idempotence
• Lints the Ansible code with ansible-lint
• Lint the Python code with flake8
• Runs the verifier tests on the nodes to ensure the desired state

Molecule (4/5)

Testing Ansible with Molecule

Molecule (5/5)

Testing Ansible with Molecule

• What can I test?
  • Files exists and permissions
  • Service are running
  • User exists and is member of the correct groups
  • Package installed
  • Basic Software interaction (Test web server basic authentication)

Molecule Demo (1/3)

• Let’s try it!!
  • Creates 2 nodes
  • Converge both nodes
  • Check for idempotence
  • Lint the Ansible and Python code
  • Verify the role against some tests
• Github Repo: github.com/luiscachog/elastic_stack (Thanks to GaRaGeD for provide a playbook to test)

Molecule Demo (2/3)

Molecule Demo (3/3)

TO-DO

• Ansible-Vault implementation
• Integrating Molecule into Travis CI, Circle CI, Jenkins, etc

Conclusion

• There are different testing solutions for Ansible, but Molecule is an Ansible-native and the robust option.
• Molecule allows you to create, converge, check idempotence, lint and verify your Ansible code.
• Molecule help you to create the best playbooks possible.

Questions?

Talk links, references and resources can be found at: luiscachog.io/talk/improve-ansible-roles-with-molecule

Thank you

You can find me on:

luiscachog [at] gmail.com | luiscachog.io | github.com/luiscachog | @luiscachog