FROM alpine:3.4

# 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 2.2
ENV RUBY_VERSION 2.2.5
ENV RUBY_DOWNLOAD_SHA256 30c4b31697a4ca4ea0c8db8ad30cf45e6690a0f09687e5d483c933c03ca335e3
ENV RUBYGEMS_VERSION 2.6.6

# some of ruby's build scripts are written in ruby
# we purge this later to make sure our final image uses what we just built
RUN set -ex \
	&& apk add --no-cache --virtual .ruby-builddeps \
		autoconf \
		bison \
		bzip2 \
		bzip2-dev \
		ca-certificates \
		coreutils \
		curl \
		gcc \
		gdbm-dev \
		glib-dev \
		libc-dev \
		libffi-dev \
		libxml2-dev \
		libxslt-dev \
		linux-headers \
		make \
		ncurses-dev \
		openssl-dev \
		procps \
# https://bugs.ruby-lang.org/issues/11869 and https://github.com/docker-library/ruby/issues/75
		readline-dev \
		ruby \
		yaml-dev \
		zlib-dev \
	&& curl -fSL -o ruby.tar.gz "https://cache.ruby-lang.org/pub/ruby/$RUBY_MAJOR/ruby-$RUBY_VERSION.tar.gz" \
	&& echo "$RUBY_DOWNLOAD_SHA256 *ruby.tar.gz" | sha256sum -c - \
	&& mkdir -p /usr/src \
	&& tar -xzf ruby.tar.gz -C /usr/src \
	&& mv "/usr/src/ruby-$RUBY_VERSION" /usr/src/ruby \
	&& rm ruby.tar.gz \
	&& cd /usr/src/ruby \
	&& { echo '#define ENABLE_PATH_CHECK 0'; echo; cat file.c; } > file.c.new && mv file.c.new file.c \
	&& autoconf \
	# the configure script does not detect isnan/isinf as macros
	&& ac_cv_func_isnan=yes ac_cv_func_isinf=yes \
		./configure --disable-install-doc \
	&& make -j"$(getconf _NPROCESSORS_ONLN)" \
	&& make install \
	&& runDeps="$( \
		scanelf --needed --nobanner --recursive /usr/local \
			| awk '{ gsub(/,/, "\nso:", $2); print "so:" $2 }' \
			| sort -u \
			| xargs -r apk info --installed \
			| sort -u \
	)" \
	&& apk add --virtual .ruby-rundeps $runDeps \
		bzip2 \
		ca-certificates \
		curl \
		libffi-dev \
		openssl-dev \
		yaml-dev \
		procps \
		zlib-dev \
	&& apk del .ruby-builddeps \
	&& gem update --system $RUBYGEMS_VERSION \
	&& rm -r /usr/src/ruby

ENV BUNDLER_VERSION 1.13.1

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" ]