Tools for Testing Ansible Roles/Playbooks and Why You Should Use Them

Transcript

1. Tools for Testing Ansible Roles/Playbooks And Why You Should Use Them Roderick R. Randolph
2. Who am I Roderick R. Randolph Opinions expressed are solely my own and do not express the views or opinions of my employer. /roderickrandolph •RRR •Raised in Amelia County, VA •Lived in Toronto for 2 years •Employed by Capital One •DevOps Architect
3. This Talk •Why Ansible •What are Ansible Roles •Importance of Testing Ansible Roles •Tools for Testing Ansible Roles •Live Demo
4. What is Ansible? Ansible is an IT automation tool. It can configure systems, deploy software, and orchestrate more advanced IT tasks such as continuous deployments or zero downtime rolling updates. http://docs.ansible.com/ansible/
5. Ansible Goals • Easy to Use No agent to install or configure • Simple Describe desired state in human-readable YAML • Secure and Reliable Uses industry standard OpenSSH utilities • Extensible Create custom modules to make Ansible even more powerful
6. # playbook.yml --- - hosts: all tasks: - name: install nginx package yum: name: nginx state: present - name: start nginx server systemd: name: nginx enabled: yes state: started Your First Playbook
7. Image Credit: https://flic.kr/p/5rQphw
8. A Month Later…
9. --- - hosts: all tasks: - name: install nginx package yum: name: nginx state: present when: ansible_os_family == 'RedHat' - name: install nginx package apt: name: nginx state: present when: ansible_os_family == 'Ubuntu' - name: copy nginx configuration in place template: src: "{{item}}.j2" dest: /etc/nginx/main.d/{{item}} mode: 0644 with_items: - nginx.conf - vhosts.conf - name: create source directory file: path: /src state: directory mode: 0755 - name: copy source code copy: src: "{{lookup('pipe', 'dirname `pwd`')}}/{{item}}" dest: /src/{{item}} with_items: - package.json - app.js - name: install npm packages npm: path: /src state: latest production: yes - name: RedHat - Ensure Java is installed yum: name: "{{ java }}" state: "present" update_cache: yes when: ansible_os_family == 'RedHat' # - name: Debian - Refresh java repo # apt: update_cache=yes # changed_when: false # when: ansible_os_family == 'Debian' - name: Debian - Ensure Java is installed apt: name={{ java }} state="present" when: ansible_os_family == 'Debian' - name: Check java version command: java -version 2>&1 | grep OpenJDK register: open_jdk changed_when: false # https://github.com/docker-library/openjdk/issues/19 - ensures tests pass due to java 8 broken certs - name: refresh the java ca-certificates command: /var/lib/dpkg/info/ca-certificates-java.postinst configure when: ansible_distribution == 'Ubuntu' and open_jdk.rc == 0 changed_when: false - name: install tomcat package yum: name: tomcat state: present when: ansible_os_family == 'RedHat' - name: install tomcat package apt: name: tomcat state: present when: ansible_os_family == 'Ubuntu' - name: install java app on server copy: src: app.war dest: /usr/share/tomcat/webapps/app.war - name: start nginx server systemd: name: nginx enabled: yes state: started with_items: ['nginx', 'tomcat']
10. Image Credi: https://flic.kr/p/7NJh8
11. Ansible offers a powerful DSL • Variables Manage data values and differences between systems • Conditionals Skip tasks based on value of variables • Loops Repeat things in one task • Templating Create dynamic expressions, filters, lookups, and tests
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13. Ansible Playbook "Code Smell" • Duplicate tasks • Large number of tasks Minimize the number of tasks to 5-6 per play • Complex loops and conditionals Ansible is not a substitute for a programming language • Hard coded variables / inconsistent naming conventions • Heavy tight coupling between roles • No tests
16. # playbook.yml --- - hosts: all roles: - nginx - tomcat - newrelic - fluentd Refactor To Use Ansible Roles
17. Ansible Roles • Provide a layer of abstraction to help organize playbook tasks (improve readability and intent) • Create reusable and common tasks that can be shared across playbooks (minimize duplication) • Breaks playbook into smaller unit of work (reduced complexity) • Can be tested independently
18. # playbook.yml --- - hosts: all roles: - newrelic - fluentd tasks: - import_role: name: nginx - include_role: name: tomcat Mix Ansible Roles With Tasks
19. Image Credit: https://flic.kr/p/77B38H
22. Importance of Testing Ansible Roles • Higher quality roles Easy to maintain, extend, comprehend • Increased confidence Fewer bugs and rework • Validate Ansible upgrade compatibility • Self-documented example use cases
23. Testing Strategies for Ansible • Unit testing Performed at the Ansible module-level • Functional testing Use Ansible to test Ansible! • Integration testing Ensures roles work together as intended
24. Tools for Testing Ansible Roles
25. https://www.ansible.com/
26. Testing Ansible with Ansible # playbook.yml --- - hosts: all tasks: - wait_for: host: "{{ inventory_hostname }}" port: 8080 delegate_to: localhost
27. Testing Ansible with Ansible # playbook.yml --- - hosts: all tasks: - uri: url: http://www.example.com return_content: yes register: webpage - fail: msg: website is unavailable when: "'AWESOME' not in webpage.content"
28. Testing Ansible with Ansible # playbook.yml --- - hosts: all tasks: - shell: /usr/bin/some-command --parameter value register: command_results - assert: that: website is unavailable - "'not ready' not in command_results.stderr" - "'gizmo enabled' in command_results.stdout"
29. https://github.com/metacloud/molecule
30. Testing Ansible with Molecule --- dependency: name: galaxy driver: name: docker lint: name: yamllint platforms: - name: centos7 image: milcom/centos7-systemd privileged: True provisioner: name: ansible scenario: name: default verifier: name: testinfra $ molecule lint $ molecule syntax $ molecule setup $ molecule idempotence $ molecule destroy ... --> Scenario: 'default' --> Action: 'lint' --> Executing Yamllint on files found... Lint completed successfully. --> Executing Flake8 on files found... Lint completed successfully. --> Executing Ansible Lint on... Lint completed successfully.
31. https://kitchen.ci/
32. Testing Ansible with Test Kitchen --- driver: name: ec2 provisioner: name: ansible_playbook platforms: - name: ubuntu-16.04 - name: centos-7 suites: - name: default verifier: name: inspec $ kitchen create $ kitchen converge $ kitchen setup $ kitchen verify $ kitchen destroy --> Running rspec test suites ✔ git binary is found in PATH 3 tests, 2 failures Finished verifying <default-ubuntu-1404> (0m0.98s). --> Destroying --> Kitchen is finished. (1m44.11s)
33. Image Credit: https://flic.kr/p/JykJBD
34. Wrap Up • Ansible playbooks and roles should be treated as code • Refactor playbooks to use ansible roles and avoid code smell • Use test tools to verify your Ansible roles to increase your confidence
35. Image Credit: https://flic.kr/p/47z3PA