如何运行与Dockerfile分开存放在单独文件夹中的python文件？

Question

i have a dockerfile which looks like this:

FROM python:3.7-slim-stretch

ENV PIP pip

RUN \
    $PIP install --upgrade pip && \
    $PIP install scikit-learn && \
    $PIP install scikit-image && \
    $PIP install rasterio && \  
    $PIP install geopandas && \ 
    $PIP install matplotlib

COPY sentools sentools
COPY data data
COPY vegetation.py .

Now in my project i have two python files vegetation and forest. i have kept each of them in separate folders. How can i create separate docker images for both python files and execute the containers for them separately?

Answer 1

If the base code is same, and only the container is supposed to run up with different Python Script, So then I will suggest using single Docker and you will not worry about the management of two docker image.

Set vegetation.py to default, when container is up without passing ENV it will run vegetation.py and if the ENV FILE_TO_RUN override during run time, the specified file will be run.

FROM python:3.7-alpine3.9 
ENV FILE_TO_RUN="/vegetation.py"
COPY vegetation.py /vegetation.py
CMD ["sh", "-c", "python $FILE_TO_RUN"]

Now, if you want to run forest.py then you can just pass the path file to ENV.

docker run -it -e FILE_TO_RUN="/forest.py" --rm my_image

or

docker run -it -e FILE_TO_RUN="/anyfile_to_run.py" --rm my_image

updated:

You can manage with args+env in your docker image.

FROM python:3.7-alpine3.9 
ARG APP="default_script.py"
ENV APP=$APP
COPY $APP /$APP
CMD ["sh", "-c", "python /$APP"]

Now build with ARGs

docker build --build-arg APP="vegetation.py" -t app_vegetation .

or

docker build --build-arg APP="forest.py" -t app_forest .

Now good to run

docker run --rm -it app_forest

copy both

FROM python:3.7-alpine3.9 
# assign some default script name to args
ARG APP="default_script.py"
ENV APP=$APP
COPY vegetation.py /vegetation.py
COPY forest.py /forest.py
CMD ["sh", "-c", "python /$APP"]

Answer 2

If you insist in creating separate images, you can always use the ARG command.

FROM python:3.7-slim-stretch
ARG file_to_copy
ENV PIP pip

RUN \
    $PIP install --upgrade pip && \
    $PIP install scikit-learn && \
    $PIP install scikit-image && \
    $PIP install rasterio && \  
    $PIP install geopandas && \ 
    $PIP install matplotlib

COPY sentools sentools
COPY data data
COPY $file_to_copy .

And the build the image like that:

docker build --buid-arg file_to_copy=vegetation.py .

or like that

docker build --buid-arg file_to_copy=forest.py .

Answer 3

When you start a Docker container, you can specify what command to run at the end of the docker run command. So you can build a single image that contains both scripts and pick which one runs when you start the container.

The scripts should be "normally" executable: they need to have the executable permission bit set, and they need to start with a line like

#!/usr/bin/env python3

and you should be able to locally (outside of Docker) run

. some_virtual_environment/bin/activate
./vegetation.py

Once you've gotten through this, you can copy the content into a Docker image

FROM python:3.7-slim-stretch
WORKDIR /app
COPY requirements.txt .
RUN pip install -r requirements.txt
COPY sentools sentools
COPY data data
COPY vegetation.py forest.py .
CMD ["./vegetation.py"]

Then you can build and run this image with either script.

docker build -t trees .
docker run --rm trees ./vegetation.py
docker run --rm trees ./forest.py

If you actually want this to be two separate images, you can create two separate Dockerfiles that differ only in their final COPY and CMD lines, and use the docker build -f option to pick which one to use.

$ tail -2 Dockerfile.vegetation
COPY vegetation.py ./
CMD ["./vegetation.py"]
$ docker build -t vegetation -f Dockerfile.vegetation .
$ docker run --rm vegetation