testing-with-lumogon.md

Testing with Lumogon

Given the ability to generate a data structure from a container or image, a desirable use case for Lumogon is introducing tests to the image build process, or building a constant-compliance style test suite for production monitoring purposes. The following is a demonstration of how simple this is building on top of Lumogon, more than it being a full example. Depending on user feedback, and the interest in the open source community, this would be a great area to explore and expand on.

Using less than 30 lines of Python we can create a framework to write tests like the following. Because of how Lumogon uses data as a first class interface it’s simple to imagine writing similar tests in other languages or testing frameworks too.

from fixtures import lumogon

image_under_test = "debian"

def test_os(lumogon):
    family = lumogon['capabilities']['host']['payload']['platformfamily']
    assert "debian" == family

def test_systemd_present(lumogon):
    packages = lumogon['capabilities']['dpkg']['payload']
    assert "systemd" in packages

def test_label_present(lumogon):
    labels = lumogon['capabilities']['label']['payload']
    assert "com.docker.compose.service" in labels

You'll find the full working example in the Lumogon repository.

The accompanying Makefile in the examples/testing-with-lumogon directory should let you try this out. This requires Python and virtualenv but otherwise you should just need to run:

make

Do try and write you're own assertions against the returned data, or change the image_under_test to your own Docker image.

These tests could be used in a CI pipeline to verify that metadata was set correctly, or that certain packages were installed, or that known-vulnerable packages (across multiple different package managers or operating systems) were not present, or that all images where using the corporate standard operating system.

If you're interested in these examples or have any questions about Lumogon then head over to our Slack channel.