Python 有没有一种方法可以；docker compose build“；利用现有的依赖关系吗？

要更改docker容器的依赖项，我运行

docker compose build

。我想更新requirements.txt上列出的依赖项，使其更具体。但每次我执行此操作时，它都会重新下载并重新安装所有需求，而不是使用现有的控制盘，甚至是满足的需求

是我遗漏了什么，还是这是默认的行为？ 是否有方法更改此行为以使用以前创建的控制盘

该项目是使用Django Cookiecutter创建的： docker=是

这是我的local.yml：

version: '3'

volumes:
  local_postgres_data: {}
  local_postgres_data_backups: {}

services:
  django:
    build:
      context: .
      dockerfile: ./compose/local/django/Dockerfile
    image: cctest_local_django
    depends_on:
      - postgres
    volumes:
      - .:/app
    env_file:
      - ./.envs/.local/.django
      - ./.envs/.local/.postgres
    ports:
      - "8000:8000"
    command: /start

  postgres:
    build:
      context: .
      dockerfile: ./compose/production/postgres/Dockerfile
    image: cctest_production_postgres
    volumes:
      - local_postgres_data:/var/lib/postgresql/data
      - local_postgres_data_backups:/backups
    env_file:
      - ./.envs/.local/.postgres

FROM python:3.6-alpine

ENV PYTHONUNBUFFERED 1

RUN apk update \
  # psycopg2 dependencies
  && apk add --virtual build-deps gcc python3-dev musl-dev \
  && apk add postgresql-dev \
  # Pillow dependencies
  && apk add jpeg-dev zlib-dev freetype-dev lcms2-dev openjpeg-dev tiff-dev tk-dev tcl-dev \
  # CFFI dependencies
  && apk add libffi-dev py-cffi \
  # Translations dependencies
  && apk add gettext \
  # https://docs.djangoproject.com/en/dev/ref/django-admin/#dbshell
  && apk add postgresql-client

# Requirements are installed here to ensure they will be cached.
COPY ./requirements /requirements
RUN pip install -r /requirements/local.txt

COPY ./compose/production/django/entrypoint /entrypoint
RUN sed -i 's/\r$//g' /entrypoint
RUN chmod +x /entrypoint

COPY ./compose/local/django/start /start
RUN sed -i 's/\r$//g' /start
RUN chmod +x /start

WORKDIR /app

ENTRYPOINT ["/entrypoint"]

Dockerfile：

version: '3'

volumes:
  local_postgres_data: {}
  local_postgres_data_backups: {}

services:
  django:
    build:
      context: .
      dockerfile: ./compose/local/django/Dockerfile
    image: cctest_local_django
    depends_on:
      - postgres
    volumes:
      - .:/app
    env_file:
      - ./.envs/.local/.django
      - ./.envs/.local/.postgres
    ports:
      - "8000:8000"
    command: /start

  postgres:
    build:
      context: .
      dockerfile: ./compose/production/postgres/Dockerfile
    image: cctest_production_postgres
    volumes:
      - local_postgres_data:/var/lib/postgresql/data
      - local_postgres_data_backups:/backups
    env_file:
      - ./.envs/.local/.postgres

FROM python:3.6-alpine

ENV PYTHONUNBUFFERED 1

RUN apk update \
  # psycopg2 dependencies
  && apk add --virtual build-deps gcc python3-dev musl-dev \
  && apk add postgresql-dev \
  # Pillow dependencies
  && apk add jpeg-dev zlib-dev freetype-dev lcms2-dev openjpeg-dev tiff-dev tk-dev tcl-dev \
  # CFFI dependencies
  && apk add libffi-dev py-cffi \
  # Translations dependencies
  && apk add gettext \
  # https://docs.djangoproject.com/en/dev/ref/django-admin/#dbshell
  && apk add postgresql-client

# Requirements are installed here to ensure they will be cached.
COPY ./requirements /requirements
RUN pip install -r /requirements/local.txt

COPY ./compose/production/django/entrypoint /entrypoint
RUN sed -i 's/\r$//g' /entrypoint
RUN chmod +x /entrypoint

COPY ./compose/local/django/start /start
RUN sed -i 's/\r$//g' /start
RUN chmod +x /start

WORKDIR /app

ENTRYPOINT ["/entrypoint"]

---

此依赖项/包是否会在初始运行时导致错误（在运行

runserver

命令时？在运行pip安装之前复制确切的requirements/local.txt，而不是整个requirements folderI，我认为您指的是每次构建映像时都会发生的requirements安装。有文档记录的行为是，更改requirements文件会使构建缓存无效。利用如果您确定需要，可以在之前构建控制盘。只需在运行pip之前将已构建的控制盘复制到控制盘缓存即可。围绕此问题的有趣（对我来说过于苛刻）解决方案：疯狂的是，没有本机方式来实现这一点。