On 23.06.2017 08:42, Frederic Lepied wrote:
On Mon, Jun 19, 2017 at 2:55 PM, Stef Walter <stefw(a)redhat.com
<mailto:stefw@redhat.com>> wrote:
Summary: I'd like to use Ansible "inventory" [0] to describe test
subjects to be tested:
http://docs.ansible.com/ansible/intro_inventory.html
<
http://docs.ansible.com/ansible/intro_inventory.html>
I've done initial exploratory work on this, pull requests below, more to
follow.
We must be careful that in the upcoming ansible 2.4, the inventory
system has been rewritten to be plugin based. It could be interesting to
use both the current version of ansible and the development version of
ansible to validate the inventory approach to avoid surprises.
Very good point. Are you referring to the inventory_plugins
configuration directive we start to see in ansible.cfg on ansible 2.3
and similar? Or something that goes further than that?
In our standard test invocation spec, we refer to "test subjects" as the
thing being tested:
https://fedoraproject.org/wiki/Changes/InvokingTests
<
https://fedoraproject.org/wiki/Changes/InvokingTests>
Mechanisms related to these test subjects have been poorly thought out
in the spec. This is my fault. Now that we're trying to implement this,
I think we can take what we've learned and update the spec.
Two areas of interest:
1. Transforming test subjects into something testable by Ansible
By using an Ansible inventory directory we can have inventory
scripts launch or prepare a system ready for the Ansible based
tests to run against it. This directory is tests/subjects
The CI testing system will launch the tests like this:
# TEST_SUBJECTS='/path/to/atomic.qcow2 /path/to/sed.rpm' \
ansible-playbook -i tests/subjects tests/tests.yml
The effect of the above command would be to run tests/tests.yml
twice, once against the qcow2 image and once against installed
rpms (in-situ testing).
Ansible supports having a directory as its inventory. All
executable files in that directory are asked to produce
inventory.
Use of an environment variable as a way to pass information
to Ansible inventory scripts is standard practice.
Although each tests *could* have their own inventory scripts,
these will commonly be shared. I've started a pull request here
related to such shared default scripts:
https://pagure.io/standard-test-roles/pull-request/9
<
https://pagure.io/standard-test-roles/pull-request/9>
You can play with these scripts. One launches a qcow2 image as
a VM and makes that VM available to Ansible via inventory. A second
inventory script installs RPMs and then tells Ansible to run
locally.
Another not yet written inventory script would launch a docker image
and tell Ansible how to connect to it. Another would configure a
module repo ... and so on.
2. A dist-git repo should describe which test subjects are applicable
Following on from the above the tests/subjects directory should
either contain executable inventory scripts that the tests would
likely use to parse $TEST_SUBJECTS into something that Ansible
can execute tests against.
$TEST_SUBJECTS is a space separated list of paths of things
to test. This is a likely bike shed topic, and I'm open to ideas
here.
Each inventory script in tests/subjects directory consumes some
different part of the environment variable(s).
Most tests will *not* want to write their own inventory scripts
and will instead just include symlinks to well known inventory
scripts in standard-test-roles.
https://pagure.io/standard-test-roles/pull-request/9
<
https://pagure.io/standard-test-roles/pull-request/9>
The symlinks are necessary, as the test *must* be in control
of describing which types of subjects, and thus Ansible inventory
it supports.
Some advanced tests (such as the Cockpit tests or IPA tests) would
launch more complex local inventory and take control of what
inventory is reported to Ansible.
On the spec side, I strongly believe that both of these things should
remain in the firm control of the tests stored in the dist-git repo.
While still having useful shared code to implement the spec.
Related: The ansible_connection=local nonsense in the current roles and
spec would be dropped.
I aim watch for discussion here on this topic for the next days or two,
and create a new wiki page with an updated spec after that:
https://fedoraproject.org/wiki/Changes/InvokingTestsAnsibleTwo
<
https://fedoraproject.org/wiki/Changes/InvokingTestsAnsibleTwo>
Could you elaborate on the capabilities that tests could request from
the CI system? And then we'll need to elaborate on conventions to
describe the usage of these capabilities in the inventories and
playbooks of the tests.
In general the tests do not request things from the CI system.
They use ansible to perform the tasks that they need. The intention is
that the tests are runnable without a CI system, and with various CI
systems, and this standard interface is the only common ground.
Do you have examples where you feel documentation is missing here?
Documentation is next up for me.
Another comment that is more general: I strongly feel that we also
need
to describe how to run the tests locally without any CI system to help
develop and debug the tests on the packagers' systems.
Indeed. This is a documentation problem. After these changes it's next
on my list to fit in ... unless someone beats me to it :)
Fred - May the source be with you