将 arg 传递给 docker build

Question

我想在 构建时间 期间传递一个变量，并在运行上使用该参数启动脚本。我该怎么做？

Dockerfile

FROM alpine
ARG var
# ENV var=${var} # doesn't work
CMD ["echo", "${var}"]
# ENTRYPOINT ["echo", "$var"] # doesn't work
# ENTRYPOINT "echo" "$var" # doesn't work

运行:

docker run -t $(docker build  --build-arg  var=hello -q .)

生产：

$var

Answer 1

Note: Unlike the shell form, the exec form does not invoke a command shell. This means that normal shell processing does not happen. For example, CMD [ "echo", "$HOME" ] will not do variable substitution on $HOME. If you want shell processing then either use the shell form or execute a shell directly, for example: CMD [ "sh", "-c", "echo $HOME" ]. When using the exec form and executing a shell directly, as in the case for the shell form, it is the shell that is doing the environment variable expansion, not docker.

换句话说，正确的 Dockerfile 应该是：

FROM alpine
ARG var
ENV var $var
CMD echo $var

为了正确构建它，您应该运行:

docker run -t $( docker build --build-arg=var=hello -q . )

来源：https://docs.docker.com/engine/reference/builder/#cmd

将 arg 传递给 docker build

Pass arg to docker build

docker

docker-build