如何在多阶段 Docker 构建的阶段之间复制变量? [英] How do I copy variables between stages of multi stage Docker build?

问题描述

我只看到了使用 COPY 在多阶段 Dockerfile 的阶段之间复制文件的示例，但是有没有办法简单地复制 ENV 变量?我的用例是从一个 git 图像开始，以获取将成为构建一部分的提交哈希.我稍后构建的图像没有 git.

I've only seen examples of using COPY to copy files between stages of a multi stage Dockerfile, but is there a way to simply copy an ENV variable? My use case is to start out with a git image to just to get the commit hash that will be part of the build. The image I'm later building with hasn't got git.

我意识到我可以将 git 哈希输出到文件并使用 COPY，但我只是想知道是否有更清洁的方法?

I realise I could just pipe out the git hash to a file and use COPY but I'm just wondering if there's a cleaner way?

推荐答案

你有 3 个选项:ARG"解决方案、基础"解决方案和文件"解决方案.

You got 3 options: The "ARG" solution, the "base" solution, and "file" solution.

ARG version_default=v1

FROM alpine:latest as base1
ARG version_default
ENV version=$version_default
RUN echo ${version}
RUN echo ${version_default}

FROM alpine:latest as base2
ARG version_default
RUN echo ${version_default}

另一种方法是将基础容器用于多个阶段:

another way is to use base container for multiple stages:

FROM alpine:latest as base
ARG version_default
ENV version=$version_default

FROM base
RUN echo ${version}

FROM base
RUN echo ${version}

您可以在此处找到更多详细信息:https://github.com/moby/moby/issues/37345

You can find more details here: https://github.com/moby/moby/issues/37345

您也可以在第一阶段将哈希保存到文件中，并在第二阶段复制该文件，然后在其中读取并使用它.

Also you could save the hash into a file in the first stage, and copy the file in the second stage and then read it and use it there.

这篇关于如何在多阶段 Docker 构建的阶段之间复制变量?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IT屋！