Docker Error standard_init_linux.go:185: exec user process caused "exec format error with Qnap TS131P

Question

My Docker file is song/songkong at https://hub.docker.com/r/songkong/songkong/~/dockerfile/

FROM openjdk:8-jre-alpine

RUN apk --no-cache add \
      ca-certificates \
      curl \
      fontconfig \
      msttcorefonts-installer \
      tini \
 && update-ms-fonts \
 && fc-cache -f

RUN mkdir -p /opt \
 && curl http://www.jthink.net/songkong/downloads/current/songkong-linux-headless-novm.tgz?val=77 | tar -C /opt -xzf - \
&& find /opt/songkong -perm /u+x -type f -print0 | xargs -0 chmod a+x

RUN addgroup -S songkong \
 && adduser -S -G songkong songkong

USER songkong:songkong

EXPOSE 4567

ENTRYPOINT ["/sbin/tini"]

# Config, License, Logs, Reports and Internal Database
VOLUME /songkong

# Music folder should be mounted here
VOLUME /music

WORKDIR /opt/songkong

CMD /opt/songkong/songkongremote8.sh

it works fine with a Synology DS218+ Disk Station (Intel)

I purchased a Qnap TS-131P to test with Qnap, but also to confirm it works with Arm processor, since Qnap supports Docker on arm processors whereas Synology does not.

When I try to start Container from the image I get an error

standard_init_linux.go:185: exec user process caused "exec format error

and this link makes me think the problem is due to the arm processor.

But I am confused since I thought the whole point of Docker was to hide these system specific details away, how (can I) fix my Docker File so it works on Qnap.

Docker won't magically make an x86 binary able to run on ARM. You'll need to rebuild an ARM image. — David Maze, Oct 11 '18 at 22:11
@DavidMaze okay but how do I do that, it is just being built with DockerHub I see no arm option, does that also mean that there should be two seperate images and that user would have to work out which one to use. — Paul Taylor, Oct 12 '18 at 06:32

Paul Taylor · Accepted Answer · 2018-10-14T10:30:09.467

The problem was indeed that Docker image files are architecture specific (at least the default ones). So a Docker file built on Intel will only work on Intel, and a Docker file build for Arm32 will only work for Arm32.

It seems there are ways to build an Arm build on an Intel device but that would still leave you with distributing two separate images. And if you have a physical Arm device it is much easier to build an Arm image directly on an Arm device.

You also need to make sure your base image supports your architecture, but the official one have now been built as multi-arch images so this is not usually a problem.

Docker Error standard_init_linux.go:185: exec user process caused "exec format error with Qnap TS131P

1 Answers1