多阶段Docker构建与诗歌和venv

不要禁用virtualenv创建功能。virtualenv在Docker构建中发挥了作用，因为它们提供了一种优雅的方式来利用多阶段构建。简而言之，构建阶段将所有内容安装到virtualenv中，而最后阶段只是将virtualenv复制到一个小映像中。

在复制代码之前，先使用诗歌导出并安装固定的需求。这将允许您使用Docker构建缓存，并且永远不会因为更改代码中的一行而重新安装依赖项。

不要使用诗意安装来安装代码，因为它将执行可编辑的安装。相反，使用诗歌构建来构建一个轮子，然后将其安装到您的virtualenv中。(感谢PEP 517，这整个过程也可以通过简单的pip install .来执行，但由于构建隔离，您最终将安装另一个Poetry副本。)

下面是一个Dockerfile安装Flask应用到Alpine镜像的例子，它依赖于Postgres。本例使用入口点脚本激活virtualenv。但一般来说，没有入口点脚本也没问题，因为您可以在CMD指令中简单地引用/venv/bin/ Python的Python二进制文件。

Dockerfile

FROM python:3.7.6-alpine3.11 as base

ENV PYTHONFAULTHANDLER=1 \
    PYTHONHASHSEED=random \
    PYTHONUNBUFFERED=1

WORKDIR /app

FROM base as builder

ENV PIP_DEFAULT_TIMEOUT=100 \
    PIP_DISABLE_PIP_VERSION_CHECK=1 \
    PIP_NO_CACHE_DIR=1 \
    POETRY_VERSION=1.0.5

RUN apk add --no-cache gcc libffi-dev musl-dev postgresql-dev
RUN pip install "poetry==$POETRY_VERSION"
RUN python -m venv /venv

COPY pyproject.toml poetry.lock ./
RUN poetry export -f requirements.txt | /venv/bin/pip install -r /dev/stdin

COPY . .
RUN poetry build && /venv/bin/pip install dist/*.whl

FROM base as final

RUN apk add --no-cache libffi libpq
COPY --from=builder /venv /venv
COPY docker-entrypoint.sh wsgi.py ./
CMD ["./docker-entrypoint.sh"]

docker-entrypoint.sh

#!/bin/sh

set -e

. /venv/bin/activate

while ! flask db upgrade
do
     echo "Retry..."
     sleep 1
done

exec gunicorn --bind 0.0.0.0:5000 --forwarded-allow-ips='*' wsgi:app

wsgi.py

import your_app

app = your_app.create_app()

博士TL;

我已经能够使用postgres为Django项目创建诗歌。在做了一些研究后，我最终得到了以下Dockerfile:

FROM python:slim

# Keeps Python from generating .pyc files in the container
ENV PYTHONDONTWRITEBYTECODE 1
# Turns off buffering for easier container logging
ENV PYTHONUNBUFFERED 1

# Install and setup poetry
RUN pip install -U pip \
    && apt-get update \
    && apt install -y curl netcat \
    && curl -sSL https://raw.githubusercontent.com/python-poetry/poetry/master/get-poetry.py | python -
ENV PATH="${PATH}:/root/.poetry/bin"

WORKDIR /usr/src/app
COPY . .
RUN poetry config virtualenvs.create false \
  && poetry install --no-interaction --no-ansi

# run entrypoint.sh
ENTRYPOINT ["/usr/src/app/entrypoint.sh"]

这是entrypoint.sh的内容:

#!/bin/sh

if [ "$DATABASE" = "postgres" ]
then
    echo "Waiting for postgres..."

    while ! nc -z $SQL_HOST $SQL_PORT; do
      sleep 0.1
    done

    echo "PostgreSQL started"
fi

python manage.py migrate

exec "$@"

详细解释

需要注意以下几点:

I have decide to use slim instead of alpine as tag for the python image because even though alpine images are supposed to reduce the size of Docker images and speed up the build, with Python, you can actually end up with a bit larger image and that takes a while to build (read this article for more info). Using this configuration builds containers faster than using the alpine image because I do not need to add some extra packages to install Python packages properly. I am installing poetry directly from the URL provided in the documentation. I am aware of the warnings provided by sobolevn. However, I consider that it is better in the long term to use the lates version of poetry by default than relying on an environment variable that I should update periodically. Updating the environment variable PATH is crucial. Otherwise, you will get an error saying that poetry was not found. Dependencies are installed directly in the python interpreter of the container. It does not create poetry to create a virtual environment before installing the dependencies.

如果你需要这个Dockerfile的alpine版本:

FROM python:alpine

# Keeps Python from generating .pyc files in the container
ENV PYTHONDONTWRITEBYTECODE 1
# Turns off buffering for easier container logging
ENV PYTHONUNBUFFERED 1

# Install dev dependencies
RUN apk update \
    && apk add curl postgresql-dev gcc python3-dev musl-dev openssl-dev libffi-dev

# Install poetry
RUN pip install -U pip \
    && curl -sSL https://raw.githubusercontent.com/python-poetry/poetry/master/get-poetry.py | python -
ENV PATH="${PATH}:/root/.poetry/bin"

WORKDIR /usr/src/app
COPY . .
RUN poetry config virtualenvs.create false \
  && poetry install --no-interaction --no-ansi

# run entrypoint.sh
ENTRYPOINT ["/usr/src/app/entrypoint.sh"]

注意，alpine版本需要一些依赖关系postgresql-dev gcc python3-dev musl-dev openssl-dev libffi-dev才能正常工作。

这是对@Claudio提供的答案的一个小修改，它使用了@sobolevn在他的回答中描述的新的诗歌安装-无根特性。

为了强制poetry将依赖项安装到特定的virtualenv中，首先需要启用它。

. /path/to/virtualenv/bin/activate && poetry install

因此，将这些添加到@Claudio的答案中

FROM python:3.10-slim as base

ENV PYTHONFAULTHANDLER=1 \
    PYTHONHASHSEED=random \
    PYTHONUNBUFFERED=1

WORKDIR /app

FROM base as builder

ENV PIP_DEFAULT_TIMEOUT=100 \
    PIP_DISABLE_PIP_VERSION_CHECK=1 \
    PIP_NO_CACHE_DIR=1 \
    POETRY_VERSION=1.3.1

RUN pip install "poetry==$POETRY_VERSION"

COPY pyproject.toml poetry.lock README.md ./
# if your project is stored in src, uncomment line below
# COPY src ./src
# or this if your file is stored in $PROJECT_NAME, assuming `myproject`
# COPY myproject ./myproject
RUN poetry config virtualenvs.in-project true && \
    poetry install --only=main --no-root && \
    poetry build

FROM base as final

COPY --from=builder /app/.venv ./.venv
COPY --from=builder /app/dist .
COPY docker-entrypoint.sh .

RUN ./.venv/bin/pip install *.whl
CMD ["./docker-entrypoint.sh"]

如果您需要将其用于开发目的，您可以通过替换这一行来添加或删除——no-dev

RUN . /venv/bin/activate && poetry install --no-dev --no-root

就像@sobolevn的回答中显示的那样

RUN . /venv/bin/activate && poetry install --no-root $(test "$YOUR_ENV" == production && echo "--no-dev")

在添加适当的环境变量声明之后。

该示例使用debian-slim的图像作为基础，但是，将其调整为基于阿尔卑斯的图像应该是一项微不足道的任务。

我看到这里所有的答案都是用pip的方式安装诗词，以避免版本问题。 如果定义为安装最合适的版本，则安装诗歌的官方方法是读取poeetry_version env变量。

在github上有一个问题，我认为这张票的解决方案非常有趣:

# `python-base` sets up all our shared environment variables
FROM python:3.8.1-slim as python-base

    # python
ENV PYTHONUNBUFFERED=1 \
    # prevents python creating .pyc files
    PYTHONDONTWRITEBYTECODE=1 \
    \
    # pip
    PIP_NO_CACHE_DIR=off \
    PIP_DISABLE_PIP_VERSION_CHECK=on \
    PIP_DEFAULT_TIMEOUT=100 \
    \
    # poetry
    # https://python-poetry.org/docs/configuration/#using-environment-variables
    POETRY_VERSION=1.0.3 \
    # make poetry install to this location
    POETRY_HOME="/opt/poetry" \
    # make poetry create the virtual environment in the project's root
    # it gets named `.venv`
    POETRY_VIRTUALENVS_IN_PROJECT=true \
    # do not ask any interactive question
    POETRY_NO_INTERACTION=1 \
    \
    # paths
    # this is where our requirements + virtual environment will live
    PYSETUP_PATH="/opt/pysetup" \
    VENV_PATH="/opt/pysetup/.venv"


# prepend poetry and venv to path
ENV PATH="$POETRY_HOME/bin:$VENV_PATH/bin:$PATH"


# `builder-base` stage is used to build deps + create our virtual environment
FROM python-base as builder-base
RUN apt-get update \
    && apt-get install --no-install-recommends -y \
        # deps for installing poetry
        curl \
        # deps for building python deps
        build-essential

# install poetry - respects $POETRY_VERSION & $POETRY_HOME
RUN curl -sSL https://raw.githubusercontent.com/sdispater/poetry/master/get-poetry.py | python

# copy project requirement files here to ensure they will be cached.
WORKDIR $PYSETUP_PATH
COPY poetry.lock pyproject.toml ./

# install runtime deps - uses $POETRY_VIRTUALENVS_IN_PROJECT internally
RUN poetry install --no-dev


# `development` image is used during development / testing
FROM python-base as development
ENV FASTAPI_ENV=development
WORKDIR $PYSETUP_PATH

# copy in our built poetry + venv
COPY --from=builder-base $POETRY_HOME $POETRY_HOME
COPY --from=builder-base $PYSETUP_PATH $PYSETUP_PATH

# quicker install as runtime deps are already installed
RUN poetry install

# will become mountpoint of our code
WORKDIR /app

EXPOSE 8000
CMD ["uvicorn", "--reload", "main:app"]


# `production` image used for runtime
FROM python-base as production
ENV FASTAPI_ENV=production
COPY --from=builder-base $PYSETUP_PATH $PYSETUP_PATH
COPY ./app /app/
WORKDIR /app
CMD ["gunicorn", "-k", "uvicorn.workers.UvicornWorker", "main:app"]

我的python应用程序的Dockerfile看起来像这样-

FROM python:3.10-alpine
RUN apk update && apk upgrade
RUN pip install -U pip poetry==1.1.13
WORKDIR /app
COPY . .
RUN poetry export --without-hashes --format=requirements.txt > requirements.txt
RUN pip install -r requirements.txt
EXPOSE 8000
ENTRYPOINT [ "python" ]
CMD ["main.py"]

下面是一个剥离的例子，其中首先是一个带有依赖关系的层(仅在这些依赖关系发生变化时构建)，然后将一个带有完整源代码的层添加到图像中。将poetry设置为安装到全局站点包中会留下一个配置工件，该配置工件也可以被删除。

FROM python:alpine

WORKDIR /app

COPY poetry.lock pyproject.toml ./
RUN pip install --no-cache-dir --upgrade pip \
 && pip install --no-cache-dir poetry \
 \
 && poetry config settings.virtualenvs.create false \
 && poetry install --no-dev \
 \
 && pip uninstall --yes poetry \

COPY . ./