One to read: Testing Ansible roles with Molecule

One to read: “Testing Ansible roles with Molecule”

This is a good brief summary of Molecule – the default testing product for Ansible (it’s now a product that the Ansible project maintains). This post also makes reference to TestInfra which is another project I need to look in to.

TestInfra really is the more interesting piece (although Molecule is interesting too), because it’s how you check exactly what is on a host. Here’s an example snippet of code (from the front page of that site’s documentation):

def test_passwd_file(host):
    passwd = host.file("/etc/passwd")
    assert passwd.contains("root")
    assert passwd.user == "root"
    assert passwd.group == "root"
    assert passwd.mode == 0o644


def test_nginx_is_installed(host):
    nginx = host.package("nginx")
    assert nginx.is_installed
    assert nginx.version.startswith("1.2")


def test_nginx_running_and_enabled(host):
    nginx = host.service("nginx")
    assert nginx.is_running
    assert nginx.is_enabled

See how easily this clearly defines what your server should look like – it’s got a file called /etc/passwd owned by root with specific permissions, and that the file contains the word root in it, likewise there is a package called nginx installed at version 1.2 and also it’s running and enabled… all good stuff, particularly from an infrastructure-as-code perspective. Now, I just need to go away and test this stuff with more diverse backgrounds than just a stock Ubuntu machine :)

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.

To respond on your own website, enter the URL of your response which should contain a link to this post's permalink URL. Your response will then appear (possibly after moderation) on this page. Want to update or remove your response? Update or delete your post and re-enter your post's URL again. (Find out more about Webmentions.)