libvirt: Testing
Description: libvirt, virtualization, virtualization API

# Testing

Different types of tests are available to libvirt developers for testing a given libvirt release.

## Unit tests

The unit test suite present in the source code is mainly used to test our XML parser/formatter, QEMU command line generator, QEMU capabilities probing, etc. It is run by developers before submitting patches upstream and is mandatory to pass for any contribution to be accepted upstream. One can run the test suite in the source tree with the following:

    $ ninja test

## Container builds

Technically speaking these are not tests in the common sense. However, usage of public container images to build libvirt in predefined and widely accessible environments makes it possible to expand our coverage across distros, architectures, toolchain flavors and library versions and as such is a very valuable marker when accepting upstream contributions. Therefore, it is recommended to run libvirt builds against your changes in various containers to either locally or by using GitLab's shared CI runners to make sure everything runs cleanly before submitting your patches. The images themselves come from libvirt's GitLab container registry, but this can be overridden if needed, see below.

### Registry

Libvirt project has its container registry hosted by GitLab at registry.gitlab.com/libvirt/libvirt which will automatically be used to pull in pre-built layers. This avoids the need to build all the containers locally using the Dockerfile recipes found in ci/containers/.

### Running container builds with GitLab CI

As long as your GitLab account has CI minutes available, pipelines will run automatically on every branch push to your fork.

### Running container jobs locally

GitLab CI configuration file is the only source of truth when it comes to various job specifications we execute as part of the upstream pipeline. Luckily, all "script" (i.e. Bash scripts) were extracted to standalone Shell functions in ci/jobs.sh. This allows users to run any of the container GitLab job specifications locally by just referencing the job name.

When it comes to actually running the GitLab jobs locally, we have a ci/helper script that can pull, build, and test (if applicable) changes on your current local branch. It supports both the Docker and Podman runtimes with an automatic selection of whichever runtime is configured on your system. In case neither has been enabled/configured, please go through the following prerequisites. We recommend using podman because of its daemonless architecture and security implications (i.e. rootless container execution by default) over Docker.

### Podman Prerequisites

Install "podman" with the system package manager.

    $ sudo dnf install -y podman
    $ podman ps

The last command should print an empty table, to verify the system is ready.

### Docker Prerequisites

Install "docker" with the system package manager and start the Docker service on your development machine, then make sure you have the privilege to run Docker commands. Typically it means setting up passwordless sudo docker command or login as root. For example:

    $ sudo dnf install -y docker
    $ # or `apt-get install docker` for Ubuntu, etc.
    $ sudo systemctl start docker
    $ sudo docker ps

The last command should print an empty table, to verify the system is ready.

An alternative method to set up permissions is by adding the current user to "docker" group and making the docker daemon socket file (by default /var/run/docker.sock) accessible to the group:

    $ sudo groupadd docker
    $ sudo usermod $USER -a -G docker
    $ sudo chown :docker /var/run/docker.sock

Note that any one of above configurations makes it possible for the user to exploit the whole host with Docker bind mounting or other privileged operations. So only do it on development machines.

### Examples of executing local container builds

All of the following examples will utilize helper script mentioned earlier sections. Let's start with the basics - listing available container images in the default libvirt registry:

    $ cd <libvirt_git>/ci
    $ ./helper --help
    $ ./helper list-images
    Available x86 container images:

    ...
    alpine-edge
    fedora-rawhide
    ...

    Available cross-compiler container images:

    ...
    debian-sid-cross-s390x
    fedora-rawhide-cross-mingw32
    fedora-rawhide-cross-mingw64
    ...

Now, let's say one would want to run the website job from GitLab on Debian 11. This is how a GitLab job specification can be referenced on ci/helper's command line:

    $ ci/helper run --job website debian-10

What if you want to run an rpmbuild of libvirt on an RPM distro?

    $ ci/helper run --job rpmbuild fedora-38

Want to use your own, say alpine-edge, container image from your GitLab container registry? Proceed with the following:

    $ ci/helper run --job build --image-prefix registry.gitlab.com/<user>/libvirt/ci- alpine-edge

Finally, it would be nice if one could get an interactive shell inside the test environment to debug potential build issues. This can be achieved with the following:

    $ ci/helper run --job shell alpine-edge

## Integration tests

There are a few frameworks for writing and running functional tests in libvirt with TCK being the one that runs in our upstream CI.

- the TCK test suite is a functional test suite implemented using the Perl bindings of libvirt. This is the recommended framework to use for writing upstream functional tests at the moment. You can start by cloning the TCK git repo.

- the Avocado VT test suite with the libvirt plugin is another framework implementing functional testing utilizing the Avocado test framework underneath. Although written in Python, the vast majority of the tests are exercising libvirt through the command line client virsh.

- the libvirt-test-API is also a functional test suite, but implemented using the Python bindings of libvirt. Unfortunately this framework is the least recommended one as it's largely unmaintained and may be completely deprecated in the future in favour of TCK. You can get it by cloning the git repo.