Docker exec /bin/sh: exec format error on Arm64

Question

My Dockerfile works on x86 machine, but fails on the machine with arm64 architecture; specifically on a1.2xlarge (an aws EC2-instance ).

Error on running docker compose up -d

#0 0.462 exec /bin/sh: exec format error
------
failed to solve: executor failed running [/bin/sh -c apt-get update]: exit code: 1

Dockerfile looks like this

FROM phusion/passenger-ruby27
ENV HOME /root
RUN apt-get update

docker -v

Docker version 20.10.17, build 100c701

uname -a

Linux Ubuntu SMP Thu Jun 9 13:06:11 UTC 2022 aarch64 aarch64 aarch64 GNU/Linux

lsb_release -a

Ubuntu 20.04.4 LTS

Answer 1

phusion/passenger-ruby27 repository separates the arm64-based images via tags (as of Nov-2022).

Ie 2.3.1 and 2.3.1-arm64

Assuming that you want to build an arm64 image on your arm64 instance, a simple way to resolve this is to pass the tag as a build argument.

Dockerfile:

ARG BASE_TAG
FROM phusion/passenger-ruby27:$BASE_TAG
ENV HOME /root
RUN apt-get update

Build examples:

# on arm
$ docker build --build-arg BASE_TAG=2.3.1-arm64 .

# on amd
$ docker build --build-arg BASE_TAG=2.3.1 .