Dumb-init Binary Hardcoded for x86 Architecture in Dockerfile, Fails on ARM Systems

[morbut-island]

Hello,

I encountered an issue when running a container built from the provided Dockerfile on ARM-based systems (e.g., Apple M1/M2, Raspberry Pi, etc.). The dumb-init binary, downloaded during the build process, is hardcoded for the x86 architecture. As a result, the container fails to run on ARM platforms due to an architecture mismatch.

Steps to Reproduce:
1. Build the Dockerfile
2. Attempt to run the resulting Docker image on an ARM-based system.
3. The container fails to start with the error: /bin/sh: /usr/local/bin/dumb-init: cannot execute binary file

A fix will would allow the image to run successfully on both x86 and ARM platforms, increasing compatibility.

[morbut-island]

Maybe adding something like this to the dockerfile:

ARG TARGETARCH
# Assign platform-specific suffix
RUN case "$TARGETARCH" in \
    "amd64") ARCH_SUFFIX="amd64" ;; \
    "arm64") ARCH_SUFFIX="aarch64" ;; \
    "arm") ARCH_SUFFIX="armv7" ;; \
    *) echo "Unsupported architecture: $TARGETARCH" && exit 1 ;; \
    esac && \
    echo "Architecture suffix set to: ${ARCH_SUFFIX}"

RUN yum install sudo -y && \
    yum install shadow-utils -y && \
    amazon-linux-extras install epel -y && \
    yum install procps-ng tar wget -y && \
    wget -O /usr/local/bin/dumb-init https://github.com/Yelp/dumb-init/releases/download/v1.2.5/dumb-init_1.2.5_${ARCH_SUFFIX} && \
    chmod +x /usr/local/bin/dumb-init && \
    groupadd --system --gid 101 ds && \
    useradd --system -g ds --no-create-home --shell /sbin/nologin --uid 101 ds && \
    rm -f /var/log/*log

TARGETARCH is available due to the use of docker buildx

@danilapog

[danilapog]

@morbut-island Hey!

Thanks for your PR.

One thing, maybe I'm wrong, but the variable ${ARCH_SUFFIX} will not be accessible between RUN

In addition, the #124 looks simpler. In any case, thanks for pointing out the problem!

[morbut-island]

Hey @danilapog!
I agree, Sacha's PR (#124) is much simpler.
Thanks