Dockerfile_base

FROM debian:bookworm-slim

SHELL ["/bin/bash", "-o", "pipefail", "-c"]

RUN apt-get update \
 && DEBIAN_FRONTEND=noninteractive apt-get install -qq -y --no-install-recommends \
      automake build-essential ca-certificates curl gettext gnupg less lzip vim pkg-config xz-utils

WORKDIR /root

RUN mkdir -p /busybox/{bin,lib}

ARG musl_version=1.2.5
ARG musl_pubkey_checksum=bf6baaa63c2c4958636850a24bb9d2d514c8b6a1b3ab9c08f3b75910fb6f57be
ARG gnu_mirror=https://ftp.snt.utwente.nl/pub/software/gnu
ARG gnu_keyring_checksum=c72adb7f24fbab0a1e1a8062b715bd47f66754cd9bad6d098101bd4755adc46e

# Download public keys
RUN curl -fsSL -o /tmp/musl.pub 'https://musl.libc.org/musl.pub' \
 && sha256sum -c <<< "${musl_pubkey_checksum}  /tmp/musl.pub" \
 && gpg --keyring musl.kbx --no-default-keyring --import /tmp/musl.pub \
 && rm /tmp/musl.pub .gnupg/*.kbx~

RUN curl -fsSL -o .gnupg/gnu-keyring.gpg "${gnu_mirror}/gnu-keyring.gpg" \
 && sha256sum -c <<< "${gnu_keyring_checksum}  .gnupg/gnu-keyring.gpg"

# Download
RUN curl -fsSL -o /tmp/musl.tar.gz "https://musl.libc.org/releases/musl-${musl_version}.tar.gz" \
 && curl -fsSL -o /tmp/musl.tar.gz.asc "https://musl.libc.org/releases/musl-${musl_version}.tar.gz.asc" \
 && gpgv --keyring musl.kbx /tmp/musl.tar.gz.asc /tmp/musl.tar.gz \
 && tar -xzf /tmp/musl.tar.gz \
 && mv musl-* musl \
 && rm -f /tmp/musl*

# Compile
RUN cd musl \
 && CFLAGS='-Os' ./configure --syslibdir=/busybox/lib \
 && make

# Install
RUN cd musl && make install \
 && for lib in /busybox/lib/*; do ln -f $(readlink $lib) $lib; done

ENV PATH="/usr/local/musl/bin:$PATH"