Testing Ansible Roles with Molecule

Testing Ansible Roles with Molecule

Transcript

1. Role over, lay down
   Testing Roles With Molecule
   Ton Kersten
   Antwerp / Belgium / 2018
   

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2. Agenda
   1 Introduction
   2 Why
   3 Question Time!
   ans-v1.25-2
   

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3. $ who am i
   ---
   - name: Ton Kersten
   creds:
   work: UNIX/Linux consultant and Trainer @ AT Computing
   linux: UNIX/Linux Geek (UNIX since 1986, Linux since 1992)
   scripting: Scripting / programming Freak
   cfgmgmt: Configuration Management Addict
   - ansible:
   - Ansible user and contributor since 2012
   - Red Hat Certified Specialist in Ansible Automation
   - Ansible Ambassador since 2015
   foss: Free and Open Source Software Enthusiast
   things: Big fan of things that just work
   ans-v1.25-3
   

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4. Why test roles
   Ansible playbooks and roles are production code
   Check installation of required packages
   Process and check needed templates
   Check files for contents
   Check running and enabled services
   Trigger handlers
   · · ·
   ans-v1.25-4
   

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5. Return of investment
   Higher role and playbook quality
   Improved reliability ⇒ Less interruptions
   Ensuring consistency
   Improve Robustness
   Automatic testing ⇒ Continues Integration / Deployment
   · · ·
   ans-v1.25-5
   

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6. Molecule
   Open Source (of course)
   Designed to test Ansible roles
   Uses Ansible to test Ansible roles
   Supports different OS’s / test scenarios
   Supports different test frameworks
   Supports multiple virtualization providers
   Setup The tools
   Molecule
   Testinfra
   Docker
   ansible-lint
   flake8
   ans-v1.25-6
   # apt-get install docker-engine
   # pip install ansible
   # pip install ansible-lint
   # pip install 'docker-py<3.0'
   # pip install molecule
   # pip install yamllint
   # pip install flake8
   # pip install testinfra
   

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7. Get started
   Version 1
   $ molecule init --role chrony --driver docker
   Version 2
   $ molecule init role \
   --role-name=chrony \
   --driver-name=docker \
   --verifier-name=testinfra
   ans-v1.25-7
   

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8. Configure linter
   molecule/default/molecule.yml (Part 1)
   lint:
   name: yamllint
   options:
   config-file: molecule/default/yamllint.cfg
   molecule/default/yamllint.cfg
   extends: default
   rules:
   line-length:
   max: 132
   level: warning
   allow-non-breakable-words: true
   allow-non-breakable-inline-mappings: false
   truthy: disable
   ans-v1.25-8
   

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9. Configure provisioner
   molecule/default/molecule.yml (Part 2)
   #
   # Ansible provisioner and variables
   #
   provisioner:
   name: ansible
   inventory:
   group_vars: # Mock data for Ansible group_vars
   all:
   name: Wile E. Coyote
   company: ACME
   domain: acme.net
   host_vars: # Mock data for Ansible host_vars
   centos7:
   foo: bar
   lint:
   name: ansible-lint
   ans-v1.25-9
   

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10. Configure verifier
    molecule/default/molecule.yml (Part 3)
    verifier:
    name: testinfra
    options:
    verbose: False
    debug: False
    lint:
    name: flake8
    options:
    ignore: "E201,E202,E203,E211,E223,E224"
    ans-v1.25-10
    E201: whitespace after char
    E202: whitespace before char
    E203: whitespace before char
    E211: whitespace before text
    E223: tab / multiple spaces before operator
    E224: tab / multiple spaces after operator
    

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11. Configure CentOS
    molecule/default/molecule.yml (Part 4)
    - name: centos7
    hostname: centos7
    image: couchbase/centos7-systemd
    image_version: latest
    privileged: True
    groups:
    - chrony
    - centos
    command: "/usr/sbin/init"
    # Mount cgroup volumes on Debian 9 host
    volumes:
    - "/sys/fs/cgroup:/sys/fs/cgroup:rw"
    ans-v1.25-11
    Run /sbin/init to startup systemd
    

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12. Configure Ubuntu
    molecule/default/molecule.yml (Part 5)
    - name: ubuntu1604
    hostname: ubuntu1604
    image: solita/ubuntu-systemd
    image_version: latest
    privileged: True
    groups:
    - chrony
    - ubuntu
    command: "/sbin/init"
    ans-v1.25-12
    Run /sbin/init to startup systemd
    

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13. Create tests 1
    molecule/default/tests/test_default.py
    import testinfra.utils.ansible_runner as ti
    # Get all hosts from the Ansible inventory
    # The inventory is generated from the molecule.yml file
    inventory = '.molecule/ansible_inventory'
    hosts = ti.AnsibleRunner(inventory).get_hosts('all')
    ans-v1.25-13
    Setup framework and get all Ansible hosts
    

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14. Create tests 2
    molecule/default/tests/test_default.py
    def test_services(host):
    try:
    facts = host.ansible("setup")["ansible_facts"]
    except host.ansible.AnsibleException as exc:
    assert exc.result['failed'] is True
    assert exc.result['msg'] == 'Error getting facts'
    osfam = facts['ansible_os_family'].lower()
    if osfam == 'debian':
    present = [ host.service('chrony') ]
    elif osfam == 'redhat':
    present = [ host.service('chronyd') ]
    else:
    raise EnvironmentError("'%s' is an unsupported OS" % osfam)
    ans-v1.25-14
    Get all Ansible facts and check OS family
    

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15. Create tests 3
    molecule/default/tests/test_default.py
    if present:
    for this in present:
    assert this.is_installed
    ans-v1.25-15
    Check if all packages are installed
    

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16. Create tests 4
    molecule/default/tests/test_default.py
    if present:
    for this in present:
    assert this.exists
    assert this.is_file
    assert this.uid == 0
    assert this.gid == 0
    assert this.mode == 0o644
    assert this.contains("# Copyright (c) 2012-today by ACME")
    ans-v1.25-16
    Check if files have the correct content and credentials
    

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17. Create tests 5
    molecule/default/tests/test_default.py
    if present:
    for this in present:
    assert this.is_running
    assert this.is_enabled
    ans-v1.25-17
    Check if all services are running and enabled
    

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18. Running tests
    molecule create
    molecule converge
    molecule verify
    Fix
    molecule login
    molecule destroy
    Correct?
    No
    Yes
    molecule test
    ans-v1.25-18
    

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19. Problems
    Fragile environment
    Versions of tools must match
    Sudden, unexpected breaking of test line
    Needs Python Docker < 3.0
    Large difference between version 1 and 2
    Documentation not always clear
    · · ·
    ans-v1.25-19
    

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20. Question Time!
    Questions??
    Contact me
    Ton.Kersten@ATComputing.nl
    http://www.atcomputing.nl
    https://github.com/tonk
    https://speakerdeck.com/tonk
    @TonKersten on Twitter
    TKersten on IRC
    Created with
    L
    A
    TEX Beamer
    Vim
    Poppler Tools
    ImageMagick
    Evince
    ans-v1.25-20
    

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