Dockerfile

FROM --platform=linux/x86_64 ruby:3.2.2-bookworm AS build

FROM alpine:3 AS sys

RUN set -xe; \
    mkdir -p /target/etc; \
    mkdir -p /blank; \
    apk --no-cache add \
      ca-certificates \
      tzdata \
    ; \
    update-ca-certificates; \
    ln -sf ../usr/share/zoneinfo/Etc/UTC /target/etc/localtime; \
    echo "Etc/UTC" > /target/etc/timezone;

FROM scratch

COPY --from=sys /target/etc /etc
COPY --from=sys /usr/share/zoneinfo/Etc/UTC /usr/share/zoneinfo/Etc/UTC
COPY --from=sys /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/ca-certificates.crt
COPY --from=sys /blank /tmp

# Ruby binary
COPY --from=build /usr/local/bin/ruby /usr/bin/ruby

# Ruby libraries
COPY --from=build /usr/local/lib/ruby /usr/local/lib/ruby

# System libraries
COPY --from=build /usr/local/lib/libruby.so.3.2 /usr/local/lib/libruby.so.3.2
COPY --from=build /lib/x86_64-linux-gnu/libz.so.1 /lib/x86_64-linux-gnu/libz.so.1
COPY --from=build /lib/x86_64-linux-gnu/libgmp.so.10 /lib/x86_64-linux-gnu/libgmp.so.10
COPY --from=build /lib/x86_64-linux-gnu/libcrypt.so.1 /lib/x86_64-linux-gnu/libcrypt.so.1
COPY --from=build /lib/x86_64-linux-gnu/libm.so.6 /lib/x86_64-linux-gnu/libm.so.6
COPY --from=build /lib/x86_64-linux-gnu/libc.so.6 /lib/x86_64-linux-gnu/libc.so.6
COPY --from=build /lib/x86_64-linux-gnu/libgcc_s.so.1 /lib/x86_64-linux-gnu/libgcc_s.so.1
COPY --from=build /lib64/ld-linux-x86-64.so.2 /lib64/ld-linux-x86-64.so.2
COPY --from=build /etc/ld.so.cache /etc/ld.so.cache

# Simple Ruby HTTP server
COPY ./server.rb /src/server.rb