Dockerfile.test

# Linux test runner. TCP_USER_TIMEOUT is a Linux-only socket option, so
# the kernel enforcement tests under test/linux and test/integration
# can't be exercised on macOS or BSD — `setsockopt` returns ENOPROTOOPT
# and the gem silently no-ops.
#
# Build:
#   docker build -f Dockerfile.test -t tcp_user_timeout:linux .
#
# Run unit + middleware tests (cross-platform):
#   docker run --rm -v $PWD:/app -w /app tcp_user_timeout:linux \
#     bash -c "bundle install && bundle exec rake test"
#
# Run kernel enforcement tests (Linux-only):
#   docker run --rm -v $PWD:/app -w /app tcp_user_timeout:linux \
#     bash -c "bundle install && bundle exec rake test:linux"
#
FROM ruby:3.3-slim

RUN apt-get update && apt-get install -y --no-install-recommends \
    build-essential \
    git \
    libyaml-dev \
    pkg-config \
  && rm -rf /var/lib/apt/lists/*

WORKDIR /app

# Use a separate volume for bundle so re-runs don't reinstall dependencies
ENV BUNDLE_PATH=/bundle BUNDLE_DISABLE_SHARED_GEMS=true

CMD ["bash"]