Docker Compose configuration for testing multiple Python versions

docker-compose.yml

name: bandersnatch-test
services:
  test-runner:
    build:
      dockerfile: 'runner.Dockerfile'
    environment:
      AWS_ACCESS_KEY: 'minioadmin'
      AWS_SECRET_ACCESS_KEY: 'minioadmin'
      AWS_EC2_METADATA_DISABLED: 'true'
      BANDERSNATCH_S3_ENDPOINT_URL: 'http://block-storage:9000'
      TOX_WORK_DIR: '/tox'
      TOX_ALWAYS_COPY: 'true'
      TOX_OVERRIDE: 'tox.envlist=py3.11,py3.12'
    volumes:
      - type: bind
        source: '../bandersnatch'
        target: '/bandersnatch'
      - type: volume
        source: tox-data
        target: /tox
    networks:
      - internal

  block-storage:
    image: 'minio/minio'
    command: 'server /data --console-address ":9001"'
    volumes:
      - type: volume
        source: minio-data
        target: /data
    # not required unless you want to run S3 tests outside the test-runner service
    # ports:
      # - "127.0.0.1:9000:9000"
      # - "127.0.0.1:9001:9001"
    networks:
      - internal

volumes:
  minio-data:
  tox-data:

networks:
  internal:

install-pythons.sh

#!/usr/bin/sh

# add deadsnakes for python versions other than the distro shipped
apt-get update
apt-get install --yes 'software-properties-common'
add-apt-repository --yes --ppa 'deadsnakes/ppa'

# install many pythons
apt-get install --yes \
    python3.10 python3.10-dev \
    python3.11 python3.11-dev \
    python3.12 python3.12-dev \
    python3-venv python3-pip

# remove downloaded files
apt-get clean

runner.Dockerfile

FROM library/ubuntu:24.04

RUN --mount=type=bind,source=install-pythons.sh,destination=/tmp/install-pythons.sh \
    ["sh", "/tmp/install-pythons.sh" ]

RUN python3 -m venv /venv
ENV PATH=/venv/bin:$PATH
RUN /venv/bin/python -m pip install --upgrade pip setuptools tox

RUN mkdir /bandersnatch
VOLUME /bandersnatch
WORKDIR /bandersnatch

CMD ["tail", "-f", "/dev/null"]

usage.md

directory placement

Expects to be in a sibling directory to the bandersnatch project root, e.g.:

- projects/
  - bandersnatch/
    - src/
    - pyproject.toml
    - ...
  - bandersnatch-test/
    - docker-compose.yml
    - runner.Dockerfile
    - install-pythons.sh

Technically this is adjustable by editing the bind mount in the volumes configuration for test-runner in the Docker Compose file.

run services

docker compose up -d

Starts 2 services:

• test-runner: an Ubuntu base image with multiple versions of Python 3 available
• block-storage: a default minio instance used as an S3-compatible object store when testing the S3 storage backend

executing tests

Running pytest:

docker compose exec test-runner tox run

This runs unit tests for Python 3.11 and 3.12. The Python versions are controlled by this line in the Docker Compose file:

TOX_OVERRIDE: 'tox.envlist=py3.11,py3.12'

You can run specific versions with -e:

docker compose exec test-runner tox run -e py3.11

And pass arguments to pytest by adding them after a --:

docker compose exec test-runner tox run -- -m 'not s3'

• TOX OVERRIDE
• tox.env_list
• built-in environment names

Running the integration test script:

docker compose exec -e TOXENV=INTEGRATION test-runner tox exec \
    -e py3.11 \
    -x testenv.allowlist_externals=*.py \
    -x testenv.pass_env+=TOXENV \
    -- ./test_runner.py