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Learn how to write comprehensive tests for your Kubernetes and OpenShift applications using the fake client and pytest.

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Testing Architecture

The openshift-python-wrapper provides a complete testing framework built on:

Fake Client

Mock Kubernetes API for testing without a cluster

Pytest

Powerful testing framework with fixtures and markers

Incremental Tests

Skip dependent tests when previous tests fail

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Setting Up Test Fixtures

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Basic Fixture Configuration

Create a conftest.py file with shared fixtures:
conftest.py
import pytest
from ocp_resources.resource import get_client

@pytest.fixture(scope="class")
def fake_client():
    """Fixture that provides a fake client for testing"""
    return get_client(fake=True)

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Resource Fixtures

Create reusable resource fixtures:
conftest.py
from ocp_resources.namespace import Namespace
from ocp_resources.pod import Pod

@pytest.fixture(scope="class")
def namespace(fake_client):
    """Create a test namespace"""
    return Namespace(client=fake_client, name="test-namespace")

@pytest.fixture(scope="class")
def pod(fake_client):
    """Create a test pod with cleanup"""
    test_pod = Pod(
        client=fake_client,
        name="test-pod",
        namespace="default",
        containers=[{"name": "test-container", "image": "nginx:latest"}],
    )
    deployed_pod = test_pod.deploy()
    yield deployed_pod
    # Cleanup after tests
    test_pod.clean_up()

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Basic Test Patterns

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CRUD Operations

Test the complete lifecycle of a resource:
test_namespace.py
import pytest
from ocp_resources.namespace import Namespace

@pytest.mark.incremental
class TestNamespace:
    @pytest.fixture(scope="class")
    def namespace(self, fake_client):
        return Namespace(
            client=fake_client,
            name="test-namespace",
        )

    def test_01_create_namespace(self, namespace):
        """Test creating Namespace"""
        deployed_resource = namespace.deploy()
        assert deployed_resource
        assert deployed_resource.name == "test-namespace"
        assert namespace.exists

    def test_02_get_namespace(self, namespace):
        """Test getting Namespace"""
        assert namespace.instance
        assert namespace.kind == "Namespace"

    def test_03_update_namespace(self, namespace):
        """Test updating Namespace"""
        resource_dict = namespace.instance.to_dict()
        resource_dict["metadata"]["labels"] = {"updated": "true"}
        namespace.update(resource_dict=resource_dict)
        assert namespace.labels["updated"] == "true"

    def test_04_delete_namespace(self, namespace):
        """Test deleting Namespace"""
        namespace.clean_up(wait=False)
        assert not namespace.exists
The @pytest.mark.incremental marker ensures that if a test fails, subsequent tests in the class are skipped.

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Testing Pods

test_pod.py
import pytest
from ocp_resources.pod import Pod

@pytest.mark.incremental
class TestPod:
    @pytest.fixture(scope="class")
    def pod(self, fake_client):
        return Pod(
            client=fake_client,
            name="test-pod",
            namespace="default",
            containers=[{"name": "test-container", "image": "nginx:latest"}],
        )

    def test_01_create_pod(self, pod):
        """Test creating Pod"""
        deployed_resource = pod.deploy()
        assert deployed_resource
        assert deployed_resource.name == "test-pod"
        assert pod.exists

    def test_02_get_pod(self, pod):
        """Test getting Pod"""
        assert pod.instance
        assert pod.kind == "Pod"
        assert pod.status == Pod.Status.RUNNING

    def test_03_update_pod(self, pod):
        """Test updating Pod"""
        resource_dict = pod.instance.to_dict()
        resource_dict["metadata"]["labels"] = {"updated": "true"}
        pod.update(resource_dict=resource_dict)
        assert pod.labels["updated"] == "true"

    def test_04_delete_pod(self, pod):
        """Test deleting Pod"""
        pod.clean_up(wait=False)
        assert not pod.exists

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Advanced Test Patterns

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Testing Resource Conditions

Test resources that may not be immediately ready:
test_conditions.py
import pytest
from ocp_resources.pod import Pod

def test_wait_for_ready_condition(fake_client):
    """Test waiting for pod to be ready"""
    pod = Pod(
        client=fake_client,
        name="test-pod",
        namespace="default",
        containers=[{"name": "nginx", "image": "nginx:latest"}],
    )
    pod.deploy()
    
    # Wait for pod to be ready
    pod.wait_for_condition(
        condition=Pod.Condition.READY,
        status=Pod.Condition.Status.TRUE,
        timeout=30
    )
    
    assert pod.exists
    pod.clean_up()

def test_not_ready_pod(fake_client):
    """Test handling of not-ready pods"""
    pod = Pod(
        client=fake_client,
        name="not-ready-pod",
        namespace="default",
        containers=[{"name": "app", "image": "myapp:latest"}],
        annotations={"fake-client.io/ready": "false"}  # Pod won't be ready
    )
    
    deployed = pod.deploy()
    
    # Verify pod is not ready
    pod.wait_for_condition(
        condition=Pod.Condition.READY,
        status=Pod.Condition.Status.FALSE,
        timeout=5
    )
    
    pod.clean_up()

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Testing Events

test_events.py
def test_resource_events(fake_client):
    """Test getting resource events"""
    from ocp_resources.pod import Pod
    
    pod = Pod(
        client=fake_client,
        name="test-pod",
        namespace="default",
        containers=[{"name": "nginx", "image": "nginx:latest"}],
    )
    pod.deploy()
    
    # Get events for the pod
    events = list(pod.events(timeout=1))
    assert events
    
    pod.clean_up()

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Testing Resource Lists

Test creating and managing multiple resources:
test_resource_lists.py
import pytest
from ocp_resources.resource import ResourceList
from ocp_resources.namespace import Namespace

@pytest.mark.incremental
class TestResourceList:
    @pytest.fixture(scope="class")
    def namespaces(self, fake_client):
        return ResourceList(
            client=fake_client,
            resource_class=Namespace,
            num_resources=3,
            name="test-namespace"
        )

    def test_resource_list_deploy(self, namespaces):
        """Test deploying multiple resources"""
        namespaces.deploy()
        assert namespaces

    def test_resource_list_len(self, namespaces):
        """Test resource list length"""
        assert len(namespaces) == 3

    def test_resource_list_name(self, namespaces):
        """Test resource naming convention"""
        for i, ns in enumerate(namespaces.resources, start=1):
            assert ns.name == f"test-namespace-{i}"

    def test_resource_list_teardown(self, namespaces):
        """Test cleaning up multiple resources"""
        namespaces.clean_up(wait=False)

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Testing Namespaced Resource Lists

test_namespaced_lists.py
import pytest
from ocp_resources.resource import NamespacedResourceList
from ocp_resources.namespace import Namespace
from ocp_resources.pod import Pod

@pytest.mark.incremental
class TestNamespacedResourceList:
    @pytest.fixture(scope="class")
    def namespaces(self, fake_client):
        return ResourceList(
            client=fake_client,
            resource_class=Namespace,
            num_resources=3,
            name="test-namespace"
        )

    @pytest.fixture(scope="class")
    def pods(self, fake_client, namespaces):
        return NamespacedResourceList(
            client=fake_client,
            resource_class=Pod,
            namespaces=namespaces,
            name="test-pod",
            containers=[{"name": "test-container", "image": "nginx:latest"}],
        )

    def test_namespaced_resource_list_deploy(self, pods):
        """Test deploying pods across namespaces"""
        pods.deploy()
        assert pods

    def test_resource_list_len(self, namespaces, pods):
        """Test one pod per namespace"""
        assert len(pods) == len(namespaces)

    def test_namespaced_resource_list_namespace(self, namespaces, pods):
        """Test pod namespace assignment"""
        for pod, namespace in zip(pods.resources, namespaces, strict=False):
            assert pod.namespace == namespace.name

    def test_resource_list_teardown(self, pods):
        """Test cleanup"""
        pods.clean_up(wait=False)

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Context Manager Testing

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Resource Context Manager

Test automatic cleanup with context managers:
test_context_manager.py
def test_resource_context_manager(fake_client):
    """Test resource cleanup with context manager"""
    from ocp_resources.secret import Secret
    
    with Secret(name="test-secret", namespace="default", client=fake_client) as sec:
        assert sec.exists
    
    # Secret should be cleaned up after context
    assert not sec.exists

def test_resource_list_context_manager(fake_client):
    """Test resource list with context manager"""
    from ocp_resources.resource import ResourceList
    from ocp_resources.namespace import Namespace
    
    with ResourceList(
        client=fake_client,
        resource_class=Namespace,
        name="test-namespace",
        num_resources=3
    ) as namespaces:
        assert len(namespaces) == 3
        for ns in namespaces.resources:
            assert ns.exists

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Testing Teardown Errors

test_teardown_errors.py
import pytest
from ocp_resources.exceptions import ResourceTeardownError
from ocp_resources.secret import Secret

class SecretTestExit(Secret):
    """Custom secret that fails to clean up"""
    def deploy(self, wait: bool = False):
        return self

    def clean_up(self, wait: bool = True, timeout: int | None = None) -> bool:
        return False

def test_resource_context_manager_exit(fake_client):
    """Test context manager with teardown failure"""
    with pytest.raises(ResourceTeardownError):
        with SecretTestExit(
            name="test-secret-exit",
            namespace="default",
            client=fake_client
        ):
            pass

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Testing Complete Applications

Test full application deployments:
test_application.py
import pytest
from ocp_resources.namespace import Namespace
from ocp_resources.deployment import Deployment
from ocp_resources.service import Service

@pytest.mark.incremental
class TestApplicationDeployment:
    """Test complete application deployment"""
    
    @pytest.fixture(scope="class")
    def namespace(self, fake_client):
        ns = Namespace(client=fake_client, name="my-app")
        ns.deploy()
        yield ns
        ns.clean_up()
    
    def test_deploy_deployment(self, fake_client, namespace):
        """Test deploying application"""
        deployment = Deployment(
            client=fake_client,
            name="backend",
            namespace=namespace.name,
            replicas=3,
            containers=[{
                "name": "api",
                "image": "myapp/backend:v1.0",
                "ports": [{"containerPort": 8080}]
            }],
            labels={"app": "backend"}
        )
        
        deployed = deployment.deploy()
        assert deployed.exists
        assert deployed.instance.spec.replicas == 3
        
        deployment.clean_up()
    
    def test_deploy_service(self, fake_client, namespace):
        """Test deploying service"""
        service = Service(
            client=fake_client,
            name="backend-service",
            namespace=namespace.name,
            selector={"app": "backend"},
            ports=[{"port": 80, "targetPort": 8080}]
        )
        
        deployed = service.deploy()
        assert deployed.exists
        assert deployed.spec.selector["app"] == "backend"
        
        service.clean_up()

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Testing Best Practices

Mark test classes with @pytest.mark.incremental to skip subsequent tests when a test fails:
@pytest.mark.incremental
class TestResource:
    def test_01_create(self):
        pass
    
    def test_02_update(self):
        # Skipped if test_01_create fails
        pass
Prefix tests with numbers to ensure execution order:
def test_01_create_resource(self):
    """Test creating resource"""
    pass

def test_02_update_resource(self):
    """Test updating resource"""
    pass
Always clean up resources in fixtures or tests:
@pytest.fixture(scope="class")
def pod(fake_client):
    pod = Pod(...)
    deployed = pod.deploy()
    yield deployed
    pod.clean_up()  # Always clean up
Test both success and failure scenarios:
def test_not_ready_resource(fake_client):
    resource = Resource(
        ...,
        annotations={"fake-client.io/ready": "false"}
    )
    deployed = resource.deploy()
    
    with pytest.raises(TimeoutError):
        resource.wait_for_condition(..., timeout=5)
Share expensive setup across tests:
@pytest.fixture(scope="class")
def namespace(fake_client):
    # Created once per test class
    ns = Namespace(...)
    ns.deploy()
    yield ns
    ns.clean_up()

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Running Tests

pytest tests/

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Debugging Tests

def test_debug_resource(fake_client):
    from ocp_resources.pod import Pod
    
    pod = Pod(...)
    deployed = pod.deploy()
    
    # Debug output
    print(f"Pod name: {pod.name}")
    print(f"Pod namespace: {pod.namespace}")
    print(f"Pod status: {pod.status}")
    print(f"Pod labels: {pod.labels}")
    
    assert deployed.exists

​
Use pytest.set_trace()

def test_debug_with_breakpoint(fake_client):
    from ocp_resources.pod import Pod
    
    pod = Pod(...)
    deployed = pod.deploy()
    
    # Set breakpoint for debugging
    pytest.set_trace()
    
    assert deployed.exists

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Next Steps

Fake Client

Learn more about the fake Kubernetes client

Class Generator

Generate wrapper classes for testing

Examples

Explore more testing examples

API Reference

Complete API documentation

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