问题描述
具有以下docker-compose文件：
Having the following docker-compose file:
db:
build: .
environment:
- MYSQL_ROOT_PASSWORD=password
- ENV=test
env_file: .env
有什么方法可以将在docker-compose.yml中声明的env变量（作为环境或在env_file中声明）用作Dockerfile的一部分，而无需在Dockerfile中声明它们？像这样的东西：
Is there any way to use the env variables declared in docker-compose.yml (either as environment or declared in the env_file) as part of Dockerfile without declaring them in the Dockerfile? Something like this:
FROM java:7
ADD ${ENV}/data.xml /data/
CMD ["run.sh"]
推荐答案
尽管这个问题是很久以前提出的，这里有一个类似问题的答案：
Although this question was asked long ago, there is an answer to a similar question here: Pass environment variables from docker-compose to container at build stage
基本上，要在容器的构建时间必须在 docker-compose.yml 中定义变量：
Basically, to use variables at the container's build time one has to define the variable in docker-compose.yml:
build:
context: .
args:
MYSQL_ROOT_PASSWORD: password
ENV: test
然后使用 ARG 在 Dockerfile 中引用它：
ARG MYSQL_ROOT_PASSWORD
ARG ENV
ADD ${ENV}/data.xml /data/
关于 *。env 文件中定义的环境变量，我相信它们不能在构建时传递给容器时间。
Concerning environment variables defined in an *.env file, I believe that they can't be passed to the container at build time.
这篇关于在Dockerbuild文件中使用docker-compose env变量的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！