引用Dockerfile中的Shell脚本变量

Question

我有一个config.sh:

IMAGE_NAME="back_end"
APP_PORT=80
PUBLIC_PORT=8080

和build.sh:

#!/bin/bash
source config.sh
echo "Image name is: ${IMAGE_NAME}"
sudo docker build -t ${IMAGE_NAME} .

和run.sh:

#!/bin/bash
source config.sh
# Expose ports and run
sudo docker run -it 
-p $PUBLIC_PORT:$APP_PORT 
--name $IMAGE_NAME $IMAGE_NAME

最后是Dockerfile:

...
CMD ["gunicorn", "-b", "0.0.0.0:${APP_PORT}", "main:app"]

我希望能够在Dockerfile中引用config.sh中的APP_PORT变量，如上所示。然而，我所拥有的不起作用，它抱怨道：Error: ${APP_PORT} is not a valid port number。所以它并没有将APP_PORT解释为一个变量。有没有办法从Dockerfile中引用config.sh中的变量？

谢谢！

编辑：基于建议解决方案的新文件(仍然不起作用(

我有一个config.sh:

IMAGE_NAME="back_end"
APP_PORT=80
PUBLIC_PORT=8080

和build.sh:

#!/bin/bash
source config.sh
echo "Image name is: ${IMAGE_NAME}"
sudo docker build --build-arg APP_PORT="${APP_PORT}" -t "${IMAGE_NAME}" .

和CCD_ 14:

#!/bin/bash
source config.sh
# Expose ports and run
sudo docker run -it 
-p $PUBLIC_PORT:$APP_PORT 
--name $IMAGE_NAME $IMAGE_NAME

最后是Dockerfile:

FROM python:buster
LABEL maintainer="..."
ARG APP_PORT
#ENV PORT $APP_PORT
ENV APP_PORT=${APP_PORT}
#RUN echo "$PORT"
# Install gunicorn & falcon
COPY requirements.txt ./
RUN pip3 install --no-cache-dir -r requirements.txt
# Add demo app
COPY ./app /app
COPY ./config.sh /app/config.sh
WORKDIR /app
RUN ls -a
CMD ["gunicorn", "-b", "0.0.0.0:${APP_PORT}", "main:app"]

run.sh仍然失败并报告：Error: '${APP_PORT} is not a valid port number.'

Answer 1

在Dockerfile中定义一个变量，如下所示：

FROM python:buster
LABEL maintainer="..."
ARG APP_PORT
ENV APP_PORT=${APP_PORT}

# Install gunicorn & falcon
COPY requirements.txt ./
RUN pip3 install --no-cache-dir -r requirements.txt
# Add demo app
COPY ./app /app
COPY ./config.sh /app/config.sh
WORKDIR /app
CMD gunicorn -b 0.0.0.0:$APP_PORT main:app     # NOTE! without separating with ["",""] 

将其作为build-arg传递，例如在您的build.sh:中

注意只有在用于构建docker映像时，才需要传递build参数。您可以在CMD上使用它，在构建docker映像时可以省略传递它。

#!/bin/bash
source config.sh
echo "Image name is: ${IMAGE_NAME}"
sudo docker build --build-arg APP_PORT="${APP_PORT}" -t "${IMAGE_NAME}" .
# sudo docker build --build-arg APP_PORT=80 -t back_end .           -> You may omit using config.sh and directly define the value of variables

启动容器时CCD_ 21在CCD_

#!/bin/bash
source config.sh
# Expose ports and run
sudo docker run -it 
-e APP_PORT=$APP_PORT 
-p $PUBLIC_PORT:$APP_PORT 
--name $IMAGE_NAME $IMAGE_NAME

Answer 2

您需要一个shell来替换环境变量，当您的CMD是exec形式时，就没有shell了。

如果使用shell形式，则存在一个shell，并且可以使用环境变量。

CMD gunicorn -b 0.0.0.0:${APP_PORT} main:app

有关CMD语句的两种形式的更多信息，请阅读此处：https://docs.docker.com/engine/reference/builder/#cmd