FROM alpine:3.6

# skip installing gem documentation
RUN mkdir -p /usr/local/etc \
    && { \
        echo 'install: --no-document'; \
        echo 'update: --no-document'; \
    } >> /usr/local/etc/gemrc

ENV RUBY_MAJOR 1.8
ENV RUBY_VERSION 1.8.7-p374
ENV RUBY_DOWNLOAD_SHA256 876eeeaaeeab10cbf4767833547d66d86d6717ef48fd3d89e27db8926a65276c

# some of ruby's build scripts are written in ruby
#   we purge system ruby later to make sure our final image uses what we just built
# readline-dev vs libedit-dev: https://bugs.ruby-lang.org/issues/11869 and https://github.com/docker-library/ruby/issues/75
RUN set -ex \
    \
    && apk add --no-cache --virtual .ruby-builddeps \
        autoconf \
        bison \
        bzip2 \
        bzip2-dev \
        ca-certificates \
        coreutils \
        dpkg-dev dpkg \
        gcc \
        gdbm-dev \
        glib-dev \
        libc-dev \
        libffi-dev \
        libressl \
        libressl-dev \
        libxml2-dev \
        libxslt-dev \
        linux-headers \
        make \
        ncurses-dev \
        procps \
        readline-dev \
        ruby \
        tar \
        xz \
        yaml-dev \
        zlib-dev \
    \
    && wget -O ruby.tar.gz "https://cache.ruby-lang.org/pub/ruby/${RUBY_MAJOR%-rc}/ruby-$RUBY_VERSION.tar.gz" \
    && echo "$RUBY_DOWNLOAD_SHA256 *ruby.tar.gz" | sha256sum -c - \
    \
    && mkdir -p /usr/src/ruby \
    && tar -xzf ruby.tar.gz -C /usr/src/ruby --strip-components=1 \
    && rm ruby.tar.gz \
    \
    && cd /usr/src/ruby \
    \
# hack in "ENABLE_PATH_CHECK" disabling to suppress:
#   warning: Insecure world writable dir
    && { \
        echo '#define ENABLE_PATH_CHECK 0'; \
        echo; \
        cat file.c; \
    } > file.c.new \
    && mv file.c.new file.c \
    \
    && autoconf \
    && gnuArch="$(dpkg-architecture --query DEB_BUILD_GNU_TYPE)" \
# the configure script does not detect isnan/isinf as macros
    && export ac_cv_func_isnan=yes ac_cv_func_isinf=yes \
    && ./configure \
        --build="$gnuArch" \
        --disable-install-doc \
        --enable-shared \
    && make -j "$(nproc)" \
    && make install \
    \
    && runDeps="$( \
        scanelf --needed --nobanner --format '%n#p' --recursive /usr/local \
            | tr ',' '\n' \
            | sort -u \
            | awk 'system("[ -e /usr/local/lib/" $1 " ]") == 0 { next } { print "so:" $1 }' \
    )" \
    && apk add --virtual .ruby-rundeps $runDeps \
        bzip2 \
        ca-certificates \
        libffi-dev \
        libressl-dev \
        procps \
        yaml-dev \
        zlib-dev \
    && apk del .ruby-builddeps \
    && cd / \
    && rm -r /usr/src/ruby \
    \
    && gem update --system

ENV BUNDLER_VERSION 1.15.4

RUN gem install bundler --version "$BUNDLER_VERSION"

# install things globally, for great justice
# and don't create ".bundle" in all our apps
ENV GEM_HOME /usr/local/bundle
ENV BUNDLE_PATH="$GEM_HOME" \
    BUNDLE_BIN="$GEM_HOME/bin" \
    BUNDLE_SILENCE_ROOT_WARNING=1 \
    BUNDLE_APP_CONFIG="$GEM_HOME"
ENV PATH $BUNDLE_BIN:$PATH
RUN mkdir -p "$GEM_HOME" "$BUNDLE_BIN" \
    && chmod 777 "$GEM_HOME" "$BUNDLE_BIN"

CMD [ "irb" ]