I'm writing a multi-stage Dockerfile for the darshan utils:
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-${DARSHAN_VER}"
...
I build it with docker build -t darshan-util:3.6.1 .
and the error I get is:
Step 5/10 : RUN curl -O "ftp://ftp.mcs.anl.gov/pub/darshan/releases/darshan-${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-${DARSHAN_VER}.tar.gz" && tar ...' returned a non-zero code: 78
I'd like to reuse the same ARG in both stages, so that I can define a default build variable just once. If I duplicate ARG in both stages, just below the two FROMs, it builds correctly.
What is the correct way to define a "global" multi-stage ARG variable with a default?
ARGs only last for the build phase of a single image. For the multistage, renew the ARG by simply stating:
ARG DARSHAN_VER
after your FROM instructions.
cf. https://docs.docker.com/engine/reference/builder/#arg
ARG DARSHAN_VER=3.1.6
FROM fedora:29 as build
ARG DARSHAN_VER
RUN dnf install -y \
gcc \
make \
bzip2 bzip2-devel zlib zlib-devel
RUN curl -O "ftp://ftp.mcs.anl.gov/pub/darshan/releases/darshan-${DARSHAN_VER}.tar.gz" \
&& tar ...
FROM fedora:29
ARG DARSHAN_VER
COPY --from=build "/usr/local/darshan-${DARSHAN_VER}" "/usr/local/darshan-${DARSHAN_VER}"
...
You will notice how I declared the initial value at the top of the script, and pull it in on each image.