Windows docker-compose args无法正常工作

Question

I'm trying to use args in a docker compose file.

The docker-compose file:

version: '3'

services:
  service1:
    image: test
    restart: always
    build:
      context: C:/ProgramData/
      dockerfile: Dockerfile
      args:
        entry: 1
    volumes:
      - C:/ProgramData/test 

The Dockerfile:

FROM microsoft/dotnet-framework:3.5
ARG entry
WORKDIR C:\\test
ADD ["/bin/x86/Release/","C:/test/"] 
ENTRYPOINT ["C:\\test\\file.exe",  ${entry}]

I don't know how exactly works the syntax in the docker file. How I have to put the arg in the ENTRYPOINT ?

Answer 1

You cannot use ARG in ENTRYPOINT (at least not directly). See How to pass ARG value to ENTRYPOINT? :

Both ARG and ENV are not expanded in ENTRYPOINT or CMD. ( https://docs.docker.com/engine/reference/builder/#environment-replacement ) However, because ENVs are passed in as part of the environment, they are available at run time, so the shell can expand them. (This means you can't use the array form of ENTRYPOINT or CMD.)

Answer 2

I solved this issue by changing the Dockerfile as follows:

FROM microsoft/dotnet-framework:3.5

ARG ENTRY
ENV my_env=$ENTRY

#RUN echo %ENTRY%
#RUN echo %my_env%

WORKDIR C:\\test
ADD ["/bin/x86/Release/","C:/test/"]

ENTRYPOINT C:/test/file.exe %my_env%