Question

我有以下文件结构

Django/
  - IoT.yml
  - Dockerfile_Build_Django
  - requirements.txt

我用于萌芽图像的dockerfile（Dockerfile_Build_Django）如下：

FROM python:3.10.0a7-alpine3.13
ENV PYTHONUNBUFFERED 1
RUN mkdir /code/
WORKDIR /usr/src/app
COPY . .
RUN pip install -r requirements.txt

我的 docker-compose 文件如下：

  Django_2.2:
    build:
      context: ./
      dockerfile: Dockerfile_Build_Django
    # Give an image name/tag
    image: python:3.10.0a7-alpine3.13 
    container_name: Django_2.2
    depends_on: 
      - Django_Mongo_4.2.12
    tty: true

在“docker-compose -f IoT.yml up”设置和运行容器之后，我使用“docker exec -it Django_2.2 /bin/sh”来SSH访问Django_2.2容器，我发现：< /p>

没有根据 docker 文件中的“RUN mkdir /code/”创建文件夹“/code”
没有根据 dockerfile 将任何内容复制到工作目录。
未根据上述 dockerfile 安装 Django。

[root@Mysite Django]# docker image ls
REPOSITORY    TAG                   IMAGE ID       CREATED       SIZE
python        3.10.0a7-alpine3.13   bba91cdea5a1   3 days ago    44.9MB
django_2.2    iot                   37c35b93c3d8   6 days ago    86.3MB

[root@MySite Django]# docker history python:3.10.0a7-alpine3.13 
IMAGE          CREATED       CREATED BY                                      SIZE      COMMENT
bba91cdea5a1   3 days ago    /bin/sh -c #(nop)  CMD ["python3"]              0B        
<missing>      3 days ago    /bin/sh -c set -ex;   wget -O get-pip.py "$P…   8.01MB    
<missing>      3 days ago    /bin/sh -c #(nop)  ENV PYTHON_GET_PIP_SHA256…   0B        
<missing>      3 days ago    /bin/sh -c #(nop)  ENV PYTHON_GET_PIP_URL=ht…   0B        
<missing>      3 days ago    /bin/sh -c #(nop)  ENV PYTHON_PIP_VERSION=21…   0B        
<missing>      3 days ago    /bin/sh -c cd /usr/local/bin  && ln -s idle3…   32B       
<missing>      3 days ago    /bin/sh -c set -ex  && apk add --no-cache --…   29.5MB    
<missing>      3 days ago    /bin/sh -c #(nop)  ENV PYTHON_VERSION=3.10.0…   0B        
<missing>      10 days ago   /bin/sh -c #(nop)  ENV GPG_KEY=A035C8C19219B…   0B        
<missing>      10 days ago   /bin/sh -c set -eux;  apk add --no-cache   c…   1.76MB    
<missing>      10 days ago   /bin/sh -c #(nop)  ENV LANG=C.UTF-8             0B        
<missing>      11 days ago   /bin/sh -c #(nop)  ENV PATH=/usr/local/bin:/…   0B        
<missing>      11 days ago   /bin/sh -c #(nop)  CMD ["/bin/sh"]              0B        
<missing>      11 days ago   /bin/sh -c #(nop) ADD file:7119167b56ff1228b…   5.61MB    

[root@MySite Django]# docker-compose -f IoT.yml build 
Django_Mongo_4.2.12 uses an image, skipping
Building Django_2.2
Sending build context to Docker daemon  2.832MB

Step 1/7 : FROM python:3.10.0a7-alpine3.13
 ---> bba91cdea5a1
Step 2/7 : ENV PYTHONUNBUFFERED 0
 ---> Running in 4f04eff80f44
Removing intermediate container 4f04eff80f44
 ---> 894fa6105e9b
Step 3/7 : RUN mkdir /code/
 ---> Running in 41a547193037
Removing intermediate container 41a547193037
 ---> 08d8a6605228
Step 4/7 : WORKDIR /usr/src/app
 ---> Running in 1d33ed47543f
Removing intermediate container 1d33ed47543f
 ---> f4f22bc9b3bb
Step 5/7 : COPY . .
 ---> 317348f86075
Step 6/7 : RUN pip install --upgrade pip
 ---> Running in e43752bea2dd
Requirement already satisfied: pip in /usr/local/lib/python3.10/site-packages (21.0.1)
Removing intermediate container e43752bea2dd
 ---> 1ce0ff9deb41
Step 7/7 : RUN pip install -r requirements.txt
 ---> Running in 87fb8a9db240
Collecting Django==2.2.17
  Downloading Django-2.2.17-py3-none-any.whl (7.5 MB)
Collecting pytz
  Downloading pytz-2021.1-py2.py3-none-any.whl (510 kB)
Collecting sqlparse>=0.2.2
  Downloading sqlparse-0.4.1-py3-none-any.whl (42 kB)
Installing collected packages: sqlparse, pytz, Django
Successfully installed Django-2.2.17 pytz-2021.1 sqlparse-0.4.1
Removing intermediate container 87fb8a9db240
 ---> 8471de36ee4d
Successfully built 8471de36ee4d
Successfully tagged python:3.10.0a7-alpine3.13
[root@MySite Django]# 

[root@MySite Django]# docker image ls
REPOSITORY    TAG                   IMAGE ID       CREATED         SIZE
python        3.10.0a7-alpine3.13   8471de36ee4d   8 minutes ago   86.5MB
python        <none>                bba91cdea5a1   3 days ago      44.9MB
django_2.2    iot                   37c35b93c3d8   6 days ago      86.3MB

我是否遗漏了 Docker 文档中的一些步骤？

Answer 1

删除我之前构建的镜像，并再次运行 docker-compose，它现在构建一个新镜像并执行 dockerfile 中的所有 RUN / COPY / CMD 命令。一切都完美无缺。基于上述行为，似乎 docker-compose 文件中的“image:”行要求 docker 守护进程检查本地是否存在此图像。如果是，则直接使用它，无需构建新的。当我手动删除该图像时，docker daemon 找不到该图像，因此构建了一个新图像。根据 Docker 官方指南，https://docs.docker.com/compose/compose-file/compose-file-v3/#build， “图像：”行仅用于重命名最终图像，永远不要说它会检查图像是否已经存在，并可能影响图像构建。官方指南在这方面并不准确和准确。

dockerfile 镜像构建中未执行 RUN 命令

1 个答案: