testshed 0.0.12

🛠️ PyTest's tool shed: Docker up, Playwright on, cleanup done

KloudKIT TestShed

A pytest plugin for integration testing with Docker and Playwright. It handles container lifecycle, browser provisioning, and cleanup automatically.

Features

• Docker management: provision and control containers from tests.
• Playwright integration: browser testing in isolated Docker environments.
• Configurable via markers & CLI: tune environments per test or suite.
• Automatic cleanup: containers and volumes are removed after tests.

Installation

pip install testshed

Usage

Fixture Auto-Discovery

TestShed fixtures are automatically available when --shed is enabled.

pytest --shed

For manual control or when --shed is not used, you can still import specific fixtures:

from kloudkit.testshed.fixtures.docker import docker_sidecar
from kloudkit.testshed.fixtures.shed import shed
from kloudkit.testshed.fixtures.playwright import playwright_browser

Docker container testing

TestShed provides fixtures to manage containers inside your tests.

Configure containers with decorators

Configure containers using pytest markers:

• @shed_config(**kwargs): pass arguments to the container factory (e.g. publish, networks).
• @shed_env(**envs): set environment variables.
• @shed_volumes(*mounts): mount volumes as (source, dest) tuples or BaseVolume instances.
• @shed_mutable(): force a dedicated container for tests that mutate state (bypasses the shared default).

from kloudkit.testshed.docker import InlineVolume, RemoteVolume

@shed_config(publish=[(8080, 80)])
@shed_env(MY_ENV_VAR="hello")
@shed_volumes(
  ("/path/to/host/data", "/app/data"),
  InlineVolume("/app/config.txt", "any content you want", mode=0o644),
  RemoteVolume("/app/remote-config.json", "https://api.example.com/config.json", mode=0o644),
)
def test_configured_docker_app(shed):
  # ... test logic ...

Use @shed_mutable() when your test writes data, installs packages, or otherwise changes the container.

This ensures it gets its own instance instead of reusing the shared default:

@shed_mutable()
def test_install_package(shed):
  shed.execute("apt-get install -y curl")

  assert "curl" in shed.execute("which curl")

High-level shed fixture

Use the shed fixture for container management with configurable defaults:

import pytest

from kloudkit.testshed.docker import Container, HttpProbe

class MyAppContainer(Container):
  DEFAULT_USER = "app"

@pytest.fixture(scope="session")
def shed_container_defaults():
  """Override this fixture to set project-specific defaults."""

  return {
    "container_class": MyAppContainer,
    "envs": {"APP_PORT": 3000},
    "probe": HttpProbe(port=3000, endpoint="/health"),
  }

def test_my_app(shed):
  # Uses your configured defaults automatically
  assert shed.execute("whoami") == "app"

@shed_env(DEBUG="true")
def test_my_app_with_debug(shed):
  # New container with override, merged with defaults
  assert shed.execute("echo $DEBUG") == "true"
  assert shed.execute("echo $APP_PORT") == "3000"

Deferred deployment with shed_deferred

Use shed_deferred when you need to control when the container starts, for pre-deployment setup, runtime parameterization, or spinning up multiple containers in a single test:

@shed_env(APP_PORT="3000")
def test_deferred_deployment(shed_deferred):
  # Container is NOT running yet — do setup here
  # ...

  # Deploy with optional call-time overrides
  container = shed_deferred(envs={"DEBUG": "true"})
  # envs are merged: APP_PORT=3000 + DEBUG=true

  assert container.execute("echo $DEBUG") == "true"
  assert container.execute("echo $APP_PORT") == "3000"


def test_multiple_containers(shed_deferred):
  primary = shed_deferred(envs={"ROLE": "primary"})
  replica = shed_deferred(envs={"ROLE": "replica"})
  # Each call spins up a new container

Call-time parameters merge with decorator config:

• envs: dict merge (call-time values override decorator values).
• volumes: concatenated (call-time volumes added after decorator volumes).
• **kwargs: passed as config args (override decorator @shed_config values).

Basic Docker container

For a lower-level API, use the docker_sidecar fixture:

def test_my_docker_app(docker_sidecar):
  # Launch a container
  nginx = docker_sidecar("nginx:latest", publish=[(8080, 80)])

  # Execute a command inside the container
  hostname = nginx.execute("cat /etc/hostname")
  assert len(hostname) > 0

  # Access the container's IP
  print(f"Container IP: {nginx.ip()}")

  # Interact with the file system
  assert "html" in nginx.fs.ls("/usr/share/nginx")

Playwright browser testing

Get a Playwright browser instance running in Docker via playwright_browser:

def test_example_website(playwright_browser):
  page = playwright_browser.new_page()
  page.goto("http://example.com")
  assert "Example Domain" in page.title()
  # ... more Playwright test logic ...

Command-line options

TestShed extends pytest with options to control the Docker environment:

• --shed: enable TestShed for the current test suite (default: disabled).
• --shed-image IMAGE: base image (e.g., ghcr.io/acme/app).
• --shed-tag TAG|SHA: image tag or digest (default: tests).
• --shed-build-context DIR: Docker build context (default: pytest.ini directory).
• --shed-image-policy POLICY: image acquisition policy (default: pull).
• --shed-skip-bootstrap: skip Docker bootstrapping (useful for unit tests).
• --shed-container-logs: print container logs on failure (default: disabled).

[!NOTE] When TestShed is installed globally, you must explicitly enable it per suite with --shed. This prevents it from configuring Docker in projects that don't use it.

Image Policies

The --shed-image-policy option controls how TestShed acquires Docker images:

• pull (default): pull image if not found locally, build as fallback.
• build: build only if image doesn't exist locally.
• require: require existing local image (fails if not found).
• rebuild: always rebuild the image.

Examples

# Enable TestShed for your suite
pytest --shed --shed-image my-test-image --shed-image-policy rebuild

# Run tests without TestShed (default)
pytest