Docker-based integration tests
Description
Simple pytest fixtures that help you write integration tests with Docker and docker-compose. Specify all necessary containers in a docker-compose.yml
file and and pytest-docker
will spin them up for the duration of your tests.
This package is tested with Python versions 3.6
, 3.7
, 3.8
and 3.9
, and pytest
version 4, 5 and 6. Python 2 is not supported.
pytest-docker
was originally created by André Caron.
Installation
Install pytest-docker
with pip
or add it to your test requirements. It is recommended to install docker-compose
python package directly in your environment to ensure that it is available during tests. This will prevent potential dependency conflicts that can occur when the system wide docker-compose
is used in tests.
Usage
Here is an example of a test that depends on a HTTP service.
With a docker-compose.yml
file like this (using the httpbin service):
version: '2'
services:
httpbin:
image: "kennethreitz/httpbin"
ports:
- "8000:80"
You can write a test like this:
import pytest
import requests
from requests.exceptions import ConnectionError
def is_responsive(url):
try:
response = requests.get(url)
if response.status_code == 200:
return True
except ConnectionError:
return False
@pytest.fixture(scope="session")
def http_service(docker_ip, docker_services):
"""Ensure that HTTP service is up and responsive."""
# `port_for` takes a container port and returns the corresponding host port
port = docker_services.port_for("httpbin", 80)
url = "http://{}:{}".format(docker_ip, port)
docker_services.wait_until_responsive(
timeout=30.0, pause=0.1, check=lambda: is_responsive(url)
)
return url
def test_status_code(http_service):
status = 418
response = requests.get(http_service + "/status/{}".format(status))
assert response.status_code == status
By default this plugin will try to open docker-compose.yml
in your tests
directory. If you need to use a custom location, override the docker_compose_file
fixture inside your conftest.py
file:
import os
import pytest
@pytest.fixture(scope="session")
def docker_compose_file(pytestconfig):
return os.path.join(str(pytestconfig.rootdir), "mycustomdir", "docker-compose.yml")
Available fixtures
All fixtures have session
scope.
docker_ip
Determine the IP address for TCP connections to Docker containers.
docker_compose_file
Get an absolute path to the docker-compose.yml
file. Override this fixture in your tests if you need a custom location.
docker_compose_project_name
Generate a project name using the current process PID. Override this fixture in your tests if you need a particular project name.
docker_services
Start all services from the docker compose file (docker-compose up
). After test are finished, shutdown all services (docker-compose down
).
docker_cleanup
Get the docker compose command to execute for test clean-up actions. Override this fixture in your tests if you need custom clean-up actions.
Development
Use of a virtual environment is recommended. See the venv package for more information.
First, install pytest-docker
and its test dependencies:
pip install -e ".[tests]"
Run tests with
pytest -c setup.cfg
to make sure that the correct configuration is used. This is also how tests are run in CI.
Use black with default settings for formatting. You can also use pylint
with setup.cfg
as the configuration file.
Contributing
This pytest plug-in and its source code are made available to you under a MIT license. It is safe to use in commercial and closed-source applications. Read the license for details!
Found a bug? Think a new feature would make this plug-in more practical? We welcome issues and pull requests!
When creating a pull request, be sure to follow this projects conventions (see above).