pytest-kind

Test your Python Kubernetes app/operator end-to-end with kind and pytest.

pytest-kind is a plugin for pytest which provides the kind_cluster fixture. The fixture will install kind 0.8.1, create a Kubernetes 1.18 cluster, and provide convenience functionality such as port forwarding.

Usage

Install pytest-kind via pip or via poetry, e.g.:

poetry add --dev pytest-kind

Write your pytest functions and use the provided kind_cluster fixture, e.g.:

def test_kubernetes_version(kind_cluster):
    assert kind_cluster.api.version == ('1', '18')

To load your custom Docker image and apply deployment manifests:

import requests
from pykube import Pod

def test_myapp(kind_cluster):
    kind_cluster.load_docker_image("myapp")
    kind_cluster.kubectl("apply", "-f", "deployment.yaml")
    kind_cluster.kubectl("rollout", "status", "deployment/myapp")

    # using Pykube to query pods
    for pod in Pod.objects(kind_cluster.api).filter(selector="app=myapp"):
        assert "Sucessfully started" in pod.logs()

    with kind_cluster.port_forward("service/myapp", 80) as port:
        r = requests.get(f"http://localhost:{port}/hello/world")
        r.raise_for_status()
        assert r.text == "Hello world!"

See the examples directory for sample projects and also check out kube-web-view which uses pytest-kind for its e2e tests.

KindCluster object

The kind_cluster fixture is an instance of the KindCluster class with the following methods:

• load_docker_image(docker_image): load the specified Docker image into the kind cluster
• kubectl(*args): run the kubectl binary against the cluster with the specified arguments. Returns the process output as string.
• port_forward(service_or_pod_name, remote_port, *args): run “kubectl port-forward” for the given service/pod and return the (random) local port. To be used as context manager (“with” statement). Pass the namespace as additional args to kubectl via “-n”, “mynamespace”.

KindCluster has the following attributes:

• name: the kind cluster name
• kubeconfig_path: the path to the Kubeconfig file to access the cluster
• kind_path: path to the kind binary
• kubectl_path: path to the kubectl binary
• api: pykube HTTPClient instance to access the cluster from Python

You can also use KindCluster directly without pytest:

from pytest_kind import KindCluster

cluster = KindCluster("myclustername")
cluster.create()
cluster.kubectl("apply", "-f", "..")
# ...
cluster.delete()

Pytest Options

The kind cluster name can be set via the --cluster-name CLI option.

The kind cluster is deleted after each pytest session, you can keep the cluster by passing --keep-cluster to pytest.

Note that you can use the PYTEST_ADDOPTS environment variable to pass these options to pytest. This also works if you call pytest from a Makefile:

# for test debugging: don't delete the kind cluster
PYTEST_ADDOPTS=--keep-cluster make test

Notes

• The kind_cluster fixture is session-scoped, i.e. the same cluster will be used across all test modules/functions.
• The kind and kubectl binaries will be downloaded once to the local directory ./.pytest-kind/{cluster-name}/. You can use them to interact with the cluster (e.g. when --keep-cluster is used).
• Some cluster pods might not be ready immediately (e.g. kind’s CoreDNS take a moment), add wait/poll functionality as required to make your tests predictable.