多级 Dockerfile 中的共享变量: 不替换 FROM 之前的 ARG

我正在为 Darshan 公司编写一个多级 Dockerfile:

ARG DARSHAN_VER=3.1.6


FROM fedora:29 as build
RUN dnf install -y \
gcc \
make \
bzip2 bzip2-devel zlib zlib-devel
RUN curl -O "ftp://ftp.mcs.anl.gov/pub/darshan/releases/darshan-${DARSHAN_VER}.tar.gz" \
&& tar ...




FROM fedora:29
COPY --from=build "/usr/local/darshan-${DARSHAN_VER}" "/usr/local/darshan-${DARSHAN_VER}"
...

我用 docker build -t darshan-util:3.6.1 .构建它，得到的错误是:

Step 5/10 : RUN curl -O "ftp://ftp.mcs.anl.gov/pub/darshan/releases/darshan-${DARSHAN_VER}.tar.gz"     && tar ...


---> Running in 9943cce1669c
% Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
...
curl: (78) RETR response: 550
The command '/bin/sh -c curl -O "ftp://ftp.mcs.anl.gov/pub/darshan/releases/darshan-${DARSHAN_VER}.tar.gz"     && tar ...' returned a non-zero code: 78

我希望在两个阶段都重用相同的 ARG，这样我就可以只定义一次默认的构建变量。 如果我在两个阶段都重复 ARG，就在两个 FROM 之下，它会正确构建。

定义默认的“全局”多级 ARG 变量的正确方法是什么？

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最佳答案

ARGs only last for the build phase of a single image. For the multistage, renew the ARG by simply stating:

ARG DARSHAN_VER

after your FROM instructions.

cf. https://docs.docker.com/engine/reference/builder/#arg

ARG DARSHAN_VER=3.1.6


FROM fedora:29 as build
ARG DARSHAN_VER
RUN dnf install -y \
gcc \
make \
bzip2 bzip2-devel zlib zlib-devel
RUN curl -O "ftp://ftp.mcs.anl.gov/pub/darshan/releases/darshan-${DARSHAN_VER}.tar.gz" \
&& tar ...




FROM fedora:29
ARG DARSHAN_VER
COPY --from=build "/usr/local/darshan-${DARSHAN_VER}" "/usr/local/darshan-${DARSHAN_VER}"
...
小开

Here are quotes from the documentation:

An ARG instruction goes out of scope at the end of the build stage where it was defined. To use an arg in multiple stages, each stage must include the ARG instruction.

https://docs.docker.com/engine/reference/builder/#scope

An ARG declared before a FROM is outside of a build stage, so it can’t be used in any instruction after a FROM. To use the default value of an ARG declared before the first FROM use an ARG instruction without a value inside of a build stage

https://docs.docker.com/engine/reference/builder/#understand-how-arg-and-from-interact


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