pytest-dockerc

pytest-dockerc is a plugin for pytest that provides support for running test from Docker Compose project. The docker-compose up -d command is executed at the beginning of the test session and the docker-compose down command at the end. The main fixture dockerc returns a compose.project.Project to deal with the python docker API in your tests. Another fixture dockerc_logs is provided to enable the logs on stdout during your tests execution.

This plugin provides a way to use as far as possible the same environment for development, test, integration and production phases. You test and deploy the same artifact in order to avoid side effects in production.

Install

pip install pytest-dockerc

Getting started

Below a basic example, you can also refer to a full example with an http server.

worktree

├── docker-compose.yml
└── tests
    ├── conftest.py
    └── test_example.py

docker-compose.yml

version: "3.6"

services:
  python:
    image: python:3-alpine

test_example.py

def test_example(dockerc):
    assert len(dockerc.containers()) == 1
    container = dockerc.containers()[0]
    assert container.is_running is True
    assert container.labels["com.docker.compose.service"] == "python"

Available options

Some options are available to update the default behavior of the plugin.

dockerc:
  --dockerc-norun       disable the run and stop commands of docker-compose
  --dockerc-attach-network
                        attach the pytest container to the docker-compose
                        network,only if pytest is started inside a container
  --dockerc-filepath=DOCKERC_FILEPATH
                        set the Compose file path
  --dockerc-projectdir=DOCKERC_PROJECTDIR
                        set the working directory of the Compose project
  --dockerc-projectname=DOCKERC_PROJECTNAME
                        set project name of the Compose project
  --dockerc-build       build images before starting containers
  --dockerc-services=DOCKERC_SERVICES
                        select services to run

Run tests without up and down command of docker-compose

Running the full docker-compose project can take time, if you loads several services. It is useful to run the test on a running instance. That method is recommended when you write a new test.

First start your docker compose like usual:

docker-compose up

Then run your tests with the --dockerc-norun, that will skip the up and down command:

pytest --dockerc-norun

Below the docker-compose output after 2 runs of the test tests/test_fixtures::test_basic_workflow, which performs a GET request.

Creating network "pytest-dockerc_default" with the default driver
Creating pytest-dockerc_http_1 ... done
Attaching to pytest-dockerc_http_1
http_1  | 192.168.32.1 - - [24/Dec/2018:08:48:21 +0000] "GET / HTTP/1.1" 200 612 "-" "python-requests/2.20.0" "-"
http_1  | 192.168.32.1 - - [24/Dec/2018:08:48:22 +0000] "GET / HTTP/1.1" 200 612 "-" "python-requests/2.20.0" "-"