在Dockerfile中的条件语句中运行 [英] RUN inside a conditional statement in Dockerfile

问题描述

我有一个 Dockerfile ，该文件当前使用以下内容：

I have a Dockerfile which currently uses the following:

COPY ./compose/local/django/start.sh /start.sh
RUN sed -i 's/\r//' /start.sh
RUN chmod +x /start.sh

您可以看到它复制了文件，然后使其可执行。现在，我需要根据构建映像时提供的参数来更改此设置。我试过使用此命令：

As you can see it copies the file and then makes it executable. I now need to change this depending on a argument provided when I build the image. I have tried using this:

RUN if [ "$arg" = "True" ]; then \
    COPY ./compose/local/django/new.sh /new.sh \
    RUN sed -i 's/\r//' /new.sh \
    RUN chmod +x /new.sh; else \
    COPY ./compose/local/django/start.sh /start.sh \
    RUN sed -i 's/\r//' /start.sh \
    RUN chmod +x /start.sh; fi

但这失败了，因为看来我不能运行 COPY 或 RUN 命令在条件语句中。它总是失败，并显示以下内容：

But this fails as it appears that I can't run COPY or RUN commands inside a conditional statement. It always fails with:

/bin/sh: 1: COPY: not found

或

/bin/sh: 1: RUN: not found

所以，我认为最好的做法是创建一个单独的bash

So, I think that the best course of action is to create a separate bash file which does the copies, something like:

#!/usr/bin/env bash

if [ "${arg}" = "True" ]; then
    echo "arg = ${arg}"
    cp ./compose/local/django/new.sh /new.sh
elif [ "${arg}" = "False" ]; then
    echo "arg = ${arg}"
    cp ./compose/local/django/start.sh /start.sh
fi

但是我在努力使复制的bash文件可执行。我知道我可以通过在命令行中运行 chmod + x 来做到这一点，但是由于我不是唯一要构建此代码的人，所以我希望会是一个更好的解决方案，就像我以前在原始 Dockerfile 脚本中所做的一样。

But I am struggling with how to make the copied bash files executable. I know I can do it by running chmod +x in the command line, but as I am not the only person who is going to be building this, I was hoping that there would be a better solution, something like I was doing previously in the original Dockerfile script.

有人可以帮助我吗？有了这个？任何帮助将不胜感激。

Can anyone help me with this? Any help would be much appreciated.

推荐答案

仅使用一个 RUN语句。这是一种最佳做法，因为它会减小图像占用的大小。

Use only one 'RUN' statement. It's a best practice as it will reduce the size taken by your image.

这是将参数传递给docker build的方式。

This is how you can pass an argument to docker build.

Dockerfile：

Dockerfile:

...
ARG NEW
COPY ./compose/local/django/new.sh /new.sh
COPY ./compose/local/django/start.sh /start.sh

RUN if [ "$NEW" = "True" ]; then \
    sed -i 's/\r//' /new.sh && \
    chmod +x /new.sh; \
  else \
    sed -i 's/\r//' /start.sh && \
    chmod +x /start.sh; \
  fi

并像这样构建它

docker build --build-arg NEW="True" .

这篇关于在Dockerfile中的条件语句中运行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IT屋！